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Solution
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Q.1 Correct
Q.1 In-correct
Q.1 Unattempt

An electron in the ground state of the hydrogen atom has the orbital radius of $5.3 \times 10^{-11} \mathrm{~m}$ while that for the electron in third excited state is $8.48 \times 10^{-10} \mathrm{~m}$. The ratio of the de Broglie wavelengths of electron in the ground state to that in the excited state is



JEE Main 2025 (Online) 22nd January Morning Shift

An electron in the ground state of the hydrogen atom has the orbital radius of $5.3 \times 10^{-11} \mathrm{~m}$ while that for the electron in third excited state is $8.48 \times 10^{-10} \mathrm{~m}$. The ratio of the de Broglie wavelengths of electron in the ground state to that in the excited state is



JEE Main 2025 (Online) 22nd January Morning Shift
Q.2 Correct
Q.2 In-correct
Q.2 Unattempt

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of



JEE Main 2025 (Online) 22nd January Morning Shift

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of



JEE Main 2025 (Online) 22nd January Morning Shift
Q.3 Correct
Q.3 In-correct
Q.3 Unattempt

A light source of wavelength $\lambda$ illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV . If the same surface is illuminated by a light source of wavelength $\frac{\lambda}{2}$, then the maximum kinetic energy of ejected electrons will be (The work function of metal is 1 eV )



JEE Main 2025 (Online) 22nd January Evening Shift

A light source of wavelength $\lambda$ illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV . If the same surface is illuminated by a light source of wavelength $\frac{\lambda}{2}$, then the maximum kinetic energy of ejected electrons will be (The work function of metal is 1 eV )



JEE Main 2025 (Online) 22nd January Evening Shift
Q.4 Correct
Q.4 In-correct
Q.4 Unattempt

A sub-atomic particle of mass $10^{-30} \mathrm{~kg}$ is moving with a velocity $2.21 \times 10^6 \mathrm{~m} / \mathrm{s}$. Under the matter wave consideration, the particle will behave closely like $\qquad$ $\left(\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J} . \mathrm{s}\right)$



JEE Main 2025 (Online) 23rd January Morning Shift

A sub-atomic particle of mass $10^{-30} \mathrm{~kg}$ is moving with a velocity $2.21 \times 10^6 \mathrm{~m} / \mathrm{s}$. Under the matter wave consideration, the particle will behave closely like $\qquad$ $\left(\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J} . \mathrm{s}\right)$



JEE Main 2025 (Online) 23rd January Morning Shift
Q.5 Correct
Q.5 In-correct
Q.5 Unattempt

In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em-wave?(Given $\mathrm{hc}=1242 \mathrm{eVnm}$ where h is the Planck's constant and c is the speed of light in vaccum.)



JEE Main 2025 (Online) 23rd January Evening Shift

In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em-wave?(Given $\mathrm{hc}=1242 \mathrm{eVnm}$ where h is the Planck's constant and c is the speed of light in vaccum.)



JEE Main 2025 (Online) 23rd January Evening Shift
Q.6 Correct
Q.6 In-correct
Q.6 Unattempt

An electron of mass ' m ' with an initial velocity $\overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0>0\right)$ enters an electric field $\overrightarrow{\mathrm{E}}=-\mathrm{E}_{\mathrm{o}} \hat{\mathrm{k}}$. If the initial de Broglie wavelength is $\lambda_0$, the value after time t would be



JEE Main 2025 (Online) 24th January Morning Shift

An electron of mass ' m ' with an initial velocity $\overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0>0\right)$ enters an electric field $\overrightarrow{\mathrm{E}}=-\mathrm{E}_{\mathrm{o}} \hat{\mathrm{k}}$. If the initial de Broglie wavelength is $\lambda_0$, the value after time t would be



JEE Main 2025 (Online) 24th January Morning Shift
Q.7 Correct
Q.7 In-correct
Q.7 Unattempt

In photoelectric effect, the stopping potential $\left(\mathrm{V}_0\right) \mathrm{v} / \mathrm{s}$ frequency $(v)$ curve is plotted.

( h is the Planck's constant and $\phi_0$ is work function of metal )

(A) $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ is linear.

(B) The slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve $=\frac{\phi_0}{\mathrm{~h}}$

(C) h constant is related to the slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ line.

(D) The value of electric charge of electron is not required to determine h using the $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve.

(E) The work function can be estimated without knowing the value of $h$.

Choose the correct answer from the options given below :



JEE Main 2025 (Online) 24th January Evening Shift

In photoelectric effect, the stopping potential $\left(\mathrm{V}_0\right) \mathrm{v} / \mathrm{s}$ frequency $(v)$ curve is plotted.

( h is the Planck's constant and $\phi_0$ is work function of metal )

(A) $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ is linear.

(B) The slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve $=\frac{\phi_0}{\mathrm{~h}}$

(C) h constant is related to the slope of $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ line.

(D) The value of electric charge of electron is not required to determine h using the $\mathrm{V}_0 \mathrm{v} / \mathrm{s} v$ curve.

(E) The work function can be estimated without knowing the value of $h$.

Choose the correct answer from the options given below :



JEE Main 2025 (Online) 24th January Evening Shift
Q.8 Correct
Q.8 In-correct
Q.8 Unattempt

A proton of mass ' $m_P$ ' has same energy as that of a photon of wavelength ' $\lambda$ '. If the proton is moving at non-relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is.



JEE Main 2025 (Online) 28th January Morning Shift

A proton of mass ' $m_P$ ' has same energy as that of a photon of wavelength ' $\lambda$ '. If the proton is moving at non-relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is.



JEE Main 2025 (Online) 28th January Morning Shift
Q.9 Correct
Q.9 In-correct
Q.9 Unattempt

Which of the following phenomena cannot be explained by wave theory of light?



JEE Main 2025 (Online) 28th January Evening Shift

Which of the following phenomena cannot be explained by wave theory of light?



JEE Main 2025 (Online) 28th January Evening Shift
Q.10 Correct
Q.10 In-correct
Q.10 Unattempt

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance.

Reason (R) : A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly with frequency of incident radiation.

In the light of the above statements, choose the most appropriate answer from the options given below :



JEE Main 2025 (Online) 29th January Morning Shift

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Emission of electrons in photoelectric effect can be suppressed by applying a sufficiently negative electron potential to the photoemissive substance.

Reason (R) : A negative electric potential, which stops the emission of electrons from the surface of a photoemissive substance, varies linearly with frequency of incident radiation.

In the light of the above statements, choose the most appropriate answer from the options given below :



JEE Main 2025 (Online) 29th January Morning Shift
Q.11 Correct
Q.11 In-correct
Q.11 Unattempt

If $\lambda$ and $K$ are de Broglie wavelength and kinetic energy, respectively, of a particle with constant mass. The correct graphical representation for the particle will be :



JEE Main 2025 (Online) 29th January Morning Shift

If $\lambda$ and $K$ are de Broglie wavelength and kinetic energy, respectively, of a particle with constant mass. The correct graphical representation for the particle will be :



JEE Main 2025 (Online) 29th January Morning Shift
Q.12 Correct
Q.12 In-correct
Q.12 Unattempt

In an experiment with photoelectric effect, the stopping potential,



JEE Main 2025 (Online) 29th January Evening Shift

In an experiment with photoelectric effect, the stopping potential,



JEE Main 2025 (Online) 29th January Evening Shift
Q.13 Correct
Q.13 In-correct
Q.13 Unattempt

A monochromatic light is incident on a metallic plate having work function $\phi$. An electron, emitted normally to the plate from a point A with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point $B$. The distance between $A$ and $B$ is :(Given : The magnitude of charge of an electron is e and mass is $\mathrm{m}, \mathrm{h}$ is Planck's constant and c is velocity of light. Take the magnetic field exists throughout the path of electron)



JEE Main 2025 (Online) 2nd April Morning Shift

A monochromatic light is incident on a metallic plate having work function $\phi$. An electron, emitted normally to the plate from a point A with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point $B$. The distance between $A$ and $B$ is :(Given : The magnitude of charge of an electron is e and mass is $\mathrm{m}, \mathrm{h}$ is Planck's constant and c is velocity of light. Take the magnetic field exists throughout the path of electron)



JEE Main 2025 (Online) 2nd April Morning Shift
Q.14 Correct
Q.14 In-correct
Q.14 Unattempt

An electron with mass ' m ' with an initial velocity $(\mathrm{t}=0) \overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0>0\right)$ enters a magnetic field $\overrightarrow{\mathrm{B}}=\mathrm{B}_0 \hat{j}$. If the initial de-Broglie wavelength at $\mathrm{t}=0$ is $\lambda_0$ then its value after time ' t ' would be :



JEE Main 2025 (Online) 2nd April Evening Shift

An electron with mass ' m ' with an initial velocity $(\mathrm{t}=0) \overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0>0\right)$ enters a magnetic field $\overrightarrow{\mathrm{B}}=\mathrm{B}_0 \hat{j}$. If the initial de-Broglie wavelength at $\mathrm{t}=0$ is $\lambda_0$ then its value after time ' t ' would be :



JEE Main 2025 (Online) 2nd April Evening Shift
Q.15 Correct
Q.15 In-correct
Q.15 Unattempt
The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2 m away from it, is

JEE Main 2025 (Online) 3rd April Morning Shift
The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2 m away from it, is

JEE Main 2025 (Online) 3rd April Morning Shift
Q.16 Correct
Q.16 In-correct
Q.16 Unattempt
The work function of a metal is 3 eV . The color of the visible light that is required to cause emission of photoelectrons is

JEE Main 2025 (Online) 3rd April Morning Shift
The work function of a metal is 3 eV . The color of the visible light that is required to cause emission of photoelectrons is

JEE Main 2025 (Online) 3rd April Morning Shift
Q.17 Correct
Q.17 In-correct
Q.17 Unattempt

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $\mathbf{R}$

Assertion A : In photoelectric effect, on increasing the intensity of incident light the stopping potential increases.

Reason R : Increase in intensity of light increases the rate of photoelectrons emitted, provided the frequency of incident light is greater than threshold frequency.

In the light of the above statements, choose the correct answer from the options given below



JEE Main 2025 (Online) 4th April Morning Shift

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason $\mathbf{R}$

Assertion A : In photoelectric effect, on increasing the intensity of incident light the stopping potential increases.

Reason R : Increase in intensity of light increases the rate of photoelectrons emitted, provided the frequency of incident light is greater than threshold frequency.

In the light of the above statements, choose the correct answer from the options given below



JEE Main 2025 (Online) 4th April Morning Shift
Q.18 Correct
Q.18 In-correct
Q.18 Unattempt

A small mirror of mass $m$ is suspended by a massless thread of length $l$. Then the small angle through which the thread will be deflected when a short pulse of laser of energy E falls normal on the mirror

($\mathrm{c}=$ speed of light in vacuum and $g=$ acceleration due to gravity)



JEE Main 2025 (Online) 4th April Morning Shift

A small mirror of mass $m$ is suspended by a massless thread of length $l$. Then the small angle through which the thread will be deflected when a short pulse of laser of energy E falls normal on the mirror

($\mathrm{c}=$ speed of light in vacuum and $g=$ acceleration due to gravity)



JEE Main 2025 (Online) 4th April Morning Shift
Q.19 Correct
Q.19 In-correct
Q.19 Unattempt

A photoemissive substance is illuminated with a radiation of wavelength $\lambda_i$ so that it releases electrons with de-Broglie wavelength $\lambda_e$. The longest wavelength of radiation that can emit photoelectron is $\lambda_o$. Expression for de-Broglie wavelength is given by:

(m: mass of the electron, h: Planck's constant and c: speed of light)



JEE Main 2025 (Online) 7th April Evening Shift

A photoemissive substance is illuminated with a radiation of wavelength $\lambda_i$ so that it releases electrons with de-Broglie wavelength $\lambda_e$. The longest wavelength of radiation that can emit photoelectron is $\lambda_o$. Expression for de-Broglie wavelength is given by:

(m: mass of the electron, h: Planck's constant and c: speed of light)



JEE Main 2025 (Online) 7th April Evening Shift
Q.20 Correct
Q.20 In-correct
Q.20 Unattempt

The ratio of the power of a light source $S_1$ to that the light source $S_2$ is $2 . S_1$ is emitting $2 \times 10^{15}$ photons per second at 600 nm . If the wavelength of the source $S_2$ is 300 nm , then the number of photons per second emitted by $S_2$ is __________ $\times 10^{14}$.



JEE Main 2025 (Online) 24th January Evening Shift

The ratio of the power of a light source $S_1$ to that the light source $S_2$ is $2 . S_1$ is emitting $2 \times 10^{15}$ photons per second at 600 nm . If the wavelength of the source $S_2$ is 300 nm , then the number of photons per second emitted by $S_2$ is __________ $\times 10^{14}$.



JEE Main 2025 (Online) 24th January Evening Shift
Q.21 Correct
Q.21 In-correct
Q.21 Unattempt

An electron is released from rest near an infinite non-conducting sheet of uniform charge density '$-\sigma$'. The rate of change of de-Broglie wave length associated with the electron varies inversely as nth power of time. The numerical value of n is _____.



JEE Main 2025 (Online) 8th April Evening Shift

An electron is released from rest near an infinite non-conducting sheet of uniform charge density '$-\sigma$'. The rate of change of de-Broglie wave length associated with the electron varies inversely as nth power of time. The numerical value of n is _____.



JEE Main 2025 (Online) 8th April Evening Shift
Q.22 Correct
Q.22 In-correct
Q.22 Unattempt
The threshold frequency of a metal with work function 6.63‌eV is :
[27-Jan-2024 Shift 2]
The threshold frequency of a metal with work function 6.63‌eV is :
[27-Jan-2024 Shift 2]
Q.23 Correct
Q.23 In-correct
Q.23 Unattempt
Two sources of light emit with a power of 200W. The ratio of number of photons of visible light emitted by each source having wavelengths 300 nm and 500‌nm respectively, will be :
[29-Jan-2024 Shift 2]
Two sources of light emit with a power of 200W. The ratio of number of photons of visible light emitted by each source having wavelengths 300 nm and 500‌nm respectively, will be :
[29-Jan-2024 Shift 2]
Q.24 Correct
Q.24 In-correct
Q.24 Unattempt
The work function of a substance is 3.0‌eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:
[30-Jan-2024 Shift 1]
The work function of a substance is 3.0‌eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:
[30-Jan-2024 Shift 1]
Q.25 Correct
Q.25 In-correct
Q.25 Unattempt
For the photoelectric effect, the maximum kinetic energy (Ek) of the photoelectrons is plotted against the frequency (v) of the incident photons as shown in figure. The slope of the graph gives

[30-Jan-2024 Shift 2]
For the photoelectric effect, the maximum kinetic energy (Ek) of the photoelectrons is plotted against the frequency (v) of the incident photons as shown in figure. The slope of the graph gives

[30-Jan-2024 Shift 2]
Q.26 Correct
Q.26 In-correct
Q.26 Unattempt
When a metal surface is illuminated by light of wavelength λ, the stopping potential is 8V. When the same surface is illuminated by light of wavelength 3λ, stopping potential is 2V. The threshold wavelength for this surface is :
[31-Jan-2024 Shift 1]
When a metal surface is illuminated by light of wavelength λ, the stopping potential is 8V. When the same surface is illuminated by light of wavelength 3λ, stopping potential is 2V. The threshold wavelength for this surface is :
[31-Jan-2024 Shift 1]
Q.27 Correct
Q.27 In-correct
Q.27 Unattempt
If the wavelength of the first member of Lyman series of hydrogen is λ. The wavelength of the second member will be
[31-Jan-2024 Shift 1]
If the wavelength of the first member of Lyman series of hydrogen is λ. The wavelength of the second member will be
[31-Jan-2024 Shift 1]
Q.28 Correct
Q.28 In-correct
Q.28 Unattempt
The de Broglie wavelengths of a proton and an α particle are λ and 2λ respectively. The ratio of the velocities of proton and α particle will be :
[1-Feb-2024 Shift 1]
The de Broglie wavelengths of a proton and an α particle are λ and 2λ respectively. The ratio of the velocities of proton and α particle will be :
[1-Feb-2024 Shift 1]
Q.29 Correct
Q.29 In-correct
Q.29 Unattempt
Monochromatic light of frequency 6×1014‌Hz is produced by a laser. The power emitted is 2×10−3W. How many photons per second on an average, are emitted by the source ?
(. Given h=6.63×10−34‌Js)
[1-Feb-2024 Shift 2]
Monochromatic light of frequency 6×1014‌Hz is produced by a laser. The power emitted is 2×10−3W. How many photons per second on an average, are emitted by the source ?
(. Given h=6.63×10−34‌Js)
[1-Feb-2024 Shift 2]
Q.30 Correct
Q.30 In-correct
Q.30 Unattempt
From the photoelectric effect experiment, following observations are made. Identify which of these are correct
A. The stopping potential depends only on the work function of the metal.
B. The saturation current increases as the intensity of incident light increases.
C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light.
D. Photoelectric effect can be explained using wave theory of light.
Choose the correct answer from the options given below:
[24-Jan-2023 Shift 1]
From the photoelectric effect experiment, following observations are made. Identify which of these are correct
A. The stopping potential depends only on the work function of the metal.
B. The saturation current increases as the intensity of incident light increases.
C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light.
D. Photoelectric effect can be explained using wave theory of light.
Choose the correct answer from the options given below:
[24-Jan-2023 Shift 1]
Q.31 Correct
Q.31 In-correct
Q.31 Unattempt
An α-particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their De-Broglie wavelength:
[24-Jan-2023 Shift 2]
An α-particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their De-Broglie wavelength:
[24-Jan-2023 Shift 2]
Q.32 Correct
Q.32 In-correct
Q.32 Unattempt
Electron beam used in an electron microscope, when accelerated by a voltage of 20‌kV. has a de-Broglie wavelength of λo. If the voltage is increased to 40‌kV. then the de-Broglie wavelength associated with the electron beam would be:
[25-Jan-2023 Shift 1]
Electron beam used in an electron microscope, when accelerated by a voltage of 20‌kV. has a de-Broglie wavelength of λo. If the voltage is increased to 40‌kV. then the de-Broglie wavelength associated with the electron beam would be:
[25-Jan-2023 Shift 1]
Q.33 Correct
Q.33 In-correct
Q.33 Unattempt
Given below are two statements :
Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below.
Options :
[25-Jan-2023 Shift 2]
Given below are two statements :
Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
In the light of above statements, choose the most appropriate answer from the options given below.
Options :
[25-Jan-2023 Shift 2]
Q.34 Correct
Q.34 In-correct
Q.34 Unattempt
The threshold wavelength for photoelectric emission from a material is 5500Å. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
A. 75W infra-red lamp
B. 10W infra-red lamp
C. 75W ultra-violet lamp
D. 10W ultra-violet lamp
Choose the correct answer from the options given below :
[29-Jan-2023 Shift 1]
The threshold wavelength for photoelectric emission from a material is 5500Å. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
A. 75W infra-red lamp
B. 10W infra-red lamp
C. 75W ultra-violet lamp
D. 10W ultra-violet lamp
Choose the correct answer from the options given below :
[29-Jan-2023 Shift 1]
Q.35 Correct
Q.35 In-correct
Q.35 Unattempt
The ratio of de-Broglie wavelength of an α-particle and a proton accelerated from rest by the same potential is ‌
1
√m
, the value of m is
[29-Jan-2023 Shift 2]
The ratio of de-Broglie wavelength of an α-particle and a proton accelerated from rest by the same potential is ‌
1
√m
, the value of m is
[29-Jan-2023 Shift 2]
Q.36 Correct
Q.36 In-correct
Q.36 Unattempt
A small object at rest, absorbs a light pulse of power 20‌mW and duration 300‌ns. Assuming speed of light as 3×108m∕ s. the momentum of the object becomes equal to :
[30-Jan-2023 Shift 1]
A small object at rest, absorbs a light pulse of power 20‌mW and duration 300‌ns. Assuming speed of light as 3×108m∕ s. the momentum of the object becomes equal to :
[30-Jan-2023 Shift 1]
Q.37 Correct
Q.37 In-correct
Q.37 Unattempt
A point source of light is placed at the centre of curvature of a hemispherical surface. The source emits a power of 24W The radius of curvature of hemisphere is 10‌cm and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is ________ ×10−8N
[30-Jan-2023 Shift 1]
A point source of light is placed at the centre of curvature of a hemispherical surface. The source emits a power of 24W The radius of curvature of hemisphere is 10‌cm and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is ________ ×10−8N
[30-Jan-2023 Shift 1]
Q.38 Correct
Q.38 In-correct
Q.38 Unattempt
An electron accelerated through a potential difference V1 has a de-Broglie wavelength of λ. When the potential is changed to V2, its de-Broglie wavelength increases by 50%. The value of (‌
V1
V2
) is equal to :
[30-Jan-2023 Shift 2]
An electron accelerated through a potential difference V1 has a de-Broglie wavelength of λ. When the potential is changed to V2, its de-Broglie wavelength increases by 50%. The value of (‌
V1
V2
) is equal to :
[30-Jan-2023 Shift 2]
Q.39 Correct
Q.39 In-correct
Q.39 Unattempt
If a source of electromagnetic radiation having power 15‌kW produces 1016 photons per second, the radiation belongs to a part of spectrum is.
(Take Planck constant h=6×10−34‌Js )
[31-Jan-2023 Shift 1]
If a source of electromagnetic radiation having power 15‌kW produces 1016 photons per second, the radiation belongs to a part of spectrum is.
(Take Planck constant h=6×10−34‌Js )
[31-Jan-2023 Shift 1]
Q.40 Correct
Q.40 In-correct
Q.40 Unattempt
If the two metals A and B are exposed to radiation of wavelength 350‌nm. The work functions of metals A and B are 4.8‌eV and 2.2‌eV. Then choose the correct option
[31-Jan-2023 Shift 2]
If the two metals A and B are exposed to radiation of wavelength 350‌nm. The work functions of metals A and B are 4.8‌eV and 2.2‌eV. Then choose the correct option
[31-Jan-2023 Shift 2]
Q.41 Correct
Q.41 In-correct
Q.41 Unattempt
A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of λ. An alpha particle having certain kinetic energy has the same de-Brogle wavelength λ. The ratio of kinetic energy of proton and that of alpha particle is:
[1-Feb-2023 Shift 1]
A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of λ. An alpha particle having certain kinetic energy has the same de-Brogle wavelength λ. The ratio of kinetic energy of proton and that of alpha particle is:
[1-Feb-2023 Shift 1]
Q.42 Correct
Q.42 In-correct
Q.42 Unattempt
The threshold frequency of metal is f0. When the light of frequency 2f0 is incident on the metal plate, the maximum velocity of photoelectron is v1. When the frequency of incident radiation is increased to 5f0. the maximum velocity of photoelectrons emitted is v2. The ratio of v1 to v2 is:
[1-Feb-2023 Shift 2]
The threshold frequency of metal is f0. When the light of frequency 2f0 is incident on the metal plate, the maximum velocity of photoelectron is v1. When the frequency of incident radiation is increased to 5f0. the maximum velocity of photoelectrons emitted is v2. The ratio of v1 to v2 is:
[1-Feb-2023 Shift 2]
Q.43 Correct
Q.43 In-correct
Q.43 Unattempt
The kinetic energy of an electron, α-particle and a proton are given as 4K,2K and K respectively. The de-Broglie wavelength associated with electron ( λe),α-particle ( λα) and the proton ( λp) are as follows :
[6-Apr-2023 shift 1]
The kinetic energy of an electron, α-particle and a proton are given as 4K,2K and K respectively. The de-Broglie wavelength associated with electron ( λe),α-particle ( λα) and the proton ( λp) are as follows :
[6-Apr-2023 shift 1]
Q.44 Correct
Q.44 In-correct
Q.44 Unattempt
The work functions of Aluminium and Gold are 4.1‌eV and and 5.1‌eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is
[6-Apr-2023 shift 2]
The work functions of Aluminium and Gold are 4.1‌eV and and 5.1‌eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is
[6-Apr-2023 shift 2]
Q.45 Correct
Q.45 In-correct
Q.45 Unattempt
Proton (P) and electron (e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, mp=1849me ):
[8-Apr-2023 shift 1]
Proton (P) and electron (e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, mp=1849me ):
[8-Apr-2023 shift 1]
Q.46 Correct
Q.46 In-correct
Q.46 Unattempt
In photoelectric effect
A. The photocurrent is proportional to the intensity of the incident radiation.
B. Maximum Kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.
C. Max K.E with which photoelectrons are emitted depends on the frequency of incident light.
D. The emission of photoelectrons require a minimum threshold intensity of incident radiation.
E. Max. K.E of the photoelectrons is independent of the frequency of the incident light.
Choose the correct answer from the options given below:
[8-Apr-2023 shift 2]
In photoelectric effect
A. The photocurrent is proportional to the intensity of the incident radiation.
B. Maximum Kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.
C. Max K.E with which photoelectrons are emitted depends on the frequency of incident light.
D. The emission of photoelectrons require a minimum threshold intensity of incident radiation.
E. Max. K.E of the photoelectrons is independent of the frequency of the incident light.
Choose the correct answer from the options given below:
[8-Apr-2023 shift 2]
Q.47 Correct
Q.47 In-correct
Q.47 Unattempt
The de Broglie wavelength of a molecule in a gas at room temperature (300K) is λ1. If the temperature of the gas is increased to 600K, then the de Broglie wavelength of the same gas molecule becomes
[10-Apr-2023 shift 1]
The de Broglie wavelength of a molecule in a gas at room temperature (300K) is λ1. If the temperature of the gas is increased to 600K, then the de Broglie wavelength of the same gas molecule becomes
[10-Apr-2023 shift 1]
Q.48 Correct
Q.48 In-correct
Q.48 Unattempt
The variation of stopping potential (V0) as a function of the frequency (v) of the incident light for a metal is shown in figure. The work function of the surface is

[10-Apr-2023 shift 2]
The variation of stopping potential (V0) as a function of the frequency (v) of the incident light for a metal is shown in figure. The work function of the surface is

[10-Apr-2023 shift 2]
Q.49 Correct
Q.49 In-correct
Q.49 Unattempt
A metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V0. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential becomes ‌
V0
4
. The threshold wavelength for this metallic surface will be
[11-Apr-2023 shift 1]
A metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V0. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential becomes ‌
V0
4
. The threshold wavelength for this metallic surface will be
[11-Apr-2023 shift 1]
Q.50 Correct
Q.50 In-correct
Q.50 Unattempt
The ratio of the de-Broglie wavelengths of proton and electron having same Kinetic energy: (Assume mp=me×1849 )
[11-Apr-2023 shift 2]
The ratio of the de-Broglie wavelengths of proton and electron having same Kinetic energy: (Assume mp=me×1849 )
[11-Apr-2023 shift 2]
Q.51 Correct
Q.51 In-correct
Q.51 Unattempt
A proton and an α-particle are accelerated from rest by 2V and 4V potentials, respectively. The ratio of their de-Broglie wavelength is :
[12-Apr-2023 shift 1]
A proton and an α-particle are accelerated from rest by 2V and 4V potentials, respectively. The ratio of their de-Broglie wavelength is :
[12-Apr-2023 shift 1]
Q.52 Correct
Q.52 In-correct
Q.52 Unattempt
The difference between threshold wavelengths for two metal surfaces A and B having work function φA=9‌eV and φB=4.5‌eV in nm is:
{ Given, hc =1242‌eV‌nm}
[13-Apr-2023 shift 1]
The difference between threshold wavelengths for two metal surfaces A and B having work function φA=9‌eV and φB=4.5‌eV in nm is:
{ Given, hc =1242‌eV‌nm}
[13-Apr-2023 shift 1]
Q.53 Correct
Q.53 In-correct
Q.53 Unattempt
The de Broglie wavelength of an electron having kinetic energy E is λ. If the kinetic energy of electron becomes ‌
E
4
, then its de-Broglie wavelength will be :
[15-Apr-2023 shift 1]
The de Broglie wavelength of an electron having kinetic energy E is λ. If the kinetic energy of electron becomes ‌
E
4
, then its de-Broglie wavelength will be :
[15-Apr-2023 shift 1]
Q.54 Correct
Q.54 In-correct
Q.54 Unattempt
When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v2. If v2=xv1, the value of x will be
[24-Jun-2022-Shift-1]
When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v2. If v2=xv1, the value of x will be
[24-Jun-2022-Shift-1]
Q.55 Correct
Q.55 In-correct
Q.55 Unattempt
The de Broglie wavelengths for an electron and a photon are λe and λp respectively. For the same kinetic energy of electron and photon, which of the following presents the correct relation between the de Broglie wavelengths of two ?
[28-Jun-2022-Shift-1]
The de Broglie wavelengths for an electron and a photon are λe and λp respectively. For the same kinetic energy of electron and photon, which of the following presents the correct relation between the de Broglie wavelengths of two ?
[28-Jun-2022-Shift-1]
Q.56 Correct
Q.56 In-correct
Q.56 Unattempt
The light of two different frequencies whose photons have energies 3.8‌eV and 1.4‌eV respectively, illuminate a metallic surface whose work function is 0.6‌eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be :
[24-Jun-2022-Shift-2]
The light of two different frequencies whose photons have energies 3.8‌eV and 1.4‌eV respectively, illuminate a metallic surface whose work function is 0.6‌eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be :
[24-Jun-2022-Shift-2]
Q.57 Correct
Q.57 In-correct
Q.57 Unattempt
Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength λ 1 and λ2, respectively are incident on a metallic surface. If λ1=3λ2 then :
[28-Jun-2022-Shift-2]
Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength λ 1 and λ2, respectively are incident on a metallic surface. If λ1=3λ2 then :
[28-Jun-2022-Shift-2]
Q.58 Correct
Q.58 In-correct
Q.58 Unattempt
Given below are two statements :
Statement I : Davisson-Germer experiment establishes the wave nature of electrons.
Statement II : If electrons have wave nature, they can interfere and show diffraction.
In the light of the above statements choose the correct answer from the option given below :
[25-Jun-2022-Shift-1]
Given below are two statements :
Statement I : Davisson-Germer experiment establishes the wave nature of electrons.
Statement II : If electrons have wave nature, they can interfere and show diffraction.
In the light of the above statements choose the correct answer from the option given below :
[25-Jun-2022-Shift-1]
Q.59 Correct
Q.59 In-correct
Q.59 Unattempt
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of a metal.
Reason R : Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.
In the light of the above statements, choose the most appropriate answer from the options given below.
[29-Jun-2022-Shift-1]
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of a metal.
Reason R : Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.
In the light of the above statements, choose the most appropriate answer from the options given below.
[29-Jun-2022-Shift-1]
Q.60 Correct
Q.60 In-correct
Q.60 Unattempt
A proton, a neutron, an electron and an α particle have same energy. If λp,λn,λe and λa are the de Broglie's wavelengths of proton, neutron, electron and α particle respectively, then choose the correct relation from the following:
[25-Jun-2022-Shift-2]
A proton, a neutron, an electron and an α particle have same energy. If λp,λn,λe and λa are the de Broglie's wavelengths of proton, neutron, electron and α particle respectively, then choose the correct relation from the following:
[25-Jun-2022-Shift-2]
Q.61 Correct
Q.61 In-correct
Q.61 Unattempt
The electric field at a point associated with a light wave is given by
E=200[sin(6×1015)‌t+sin(9×1015)‌t]V−1
Given : h=4.14×10−15‌eVs
If this light falls on a metal surface having a work function of 2.50‌eV, the maximum kinetic energy of the photoelectrons will be
[29-Jun-2022-Shift-2]
The electric field at a point associated with a light wave is given by
E=200[sin(6×1015)‌t+sin(9×1015)‌t]V−1
Given : h=4.14×10−15‌eVs
If this light falls on a metal surface having a work function of 2.50‌eV, the maximum kinetic energy of the photoelectrons will be
[29-Jun-2022-Shift-2]
Q.62 Correct
Q.62 In-correct
Q.62 Unattempt
An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe and that of photon are Eph and pph respectively. Which of the following is correct?
[26-Jun-2022-Shift-1]
An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe and that of photon are Eph and pph respectively. Which of the following is correct?
[26-Jun-2022-Shift-1]
Q.63 Correct
Q.63 In-correct
Q.63 Unattempt
The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630
o
A
 is 0.42V. If the threshold frequency is x×1013∕s, where x is____ (nearest integer).
(Given, speed light =3×108m∕s, Planck's constant =6.63×10−34‌Js )
[26-Jun-2022-Shift-2]
The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630
o
A
 is 0.42V. If the threshold frequency is x×1013∕s, where x is____ (nearest integer).
(Given, speed light =3×108m∕s, Planck's constant =6.63×10−34‌Js )
[26-Jun-2022-Shift-2]
Q.64 Correct
Q.64 In-correct
Q.64 Unattempt
An α particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelengths (λα:λC12) is :
[27-Jun-2022-Shift-1]
An α particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelengths (λα:λC12) is :
[27-Jun-2022-Shift-1]
Q.65 Correct
Q.65 In-correct
Q.65 Unattempt
Given below are two statements :
Statement I : In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit (E .E1) to higher energy orbit (E2), is given as hf=E1−E2
Statement II : The jumping of electron from higher energy orbit (E2) to lower energy orbit (E1) is associated with frequency of radiation given as f=(E2−E1)∕h
This condition is Bohr's frequency condition.
In the light of the above statements, choose the correct answer from the options given below :
[27-Jun-2022-Shift-2]
Given below are two statements :
Statement I : In hydrogen atom, the frequency of radiation emitted when an electron jumps from lower energy orbit (E .E1) to higher energy orbit (E2), is given as hf=E1−E2
Statement II : The jumping of electron from higher energy orbit (E2) to lower energy orbit (E1) is associated with frequency of radiation given as f=(E2−E1)∕h
This condition is Bohr's frequency condition.
In the light of the above statements, choose the correct answer from the options given below :
[27-Jun-2022-Shift-2]
Q.66 Correct
Q.66 In-correct
Q.66 Unattempt
A metal exposed to light of wavelength 800nm and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength 500nm is used. The work function of the metal is : (Take hc =1230eV−nm ).
[25-Jul-2022-Shift-1]
A metal exposed to light of wavelength 800nm and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength 500nm is used. The work function of the metal is : (Take hc =1230eV−nm ).
[25-Jul-2022-Shift-1]
Q.67 Correct
Q.67 In-correct
Q.67 Unattempt
The energy band gap of semiconducting material to produce violet (wavelength =4000
o
A
 ) LED is eV. (Round off to the nearest integer).
[25-Jul-2022-Shift-1]
The energy band gap of semiconducting material to produce violet (wavelength =4000
o
A
 ) LED is eV. (Round off to the nearest integer).
[25-Jul-2022-Shift-1]
Q.68 Correct
Q.68 In-correct
Q.68 Unattempt
The ratio of wavelengths of proton and deuteron accelerated by potential Vp and Vd is 1:√2. Then the ratio of Vp to Vd will be :
[25-Jul-2022-Shift-2]
The ratio of wavelengths of proton and deuteron accelerated by potential Vp and Vd is 1:√2. Then the ratio of Vp to Vd will be :
[25-Jul-2022-Shift-2]
Q.69 Correct
Q.69 In-correct
Q.69 Unattempt
A parallel beam of light of wavelength 900‌nm and intensity 100Wm−2 is incident on a surface perpendicular to the beam. The number of photons crossing 1cm2 area perpendicular to the beam in one second is :
[26-Jul-2022-Shift-1]
A parallel beam of light of wavelength 900‌nm and intensity 100Wm−2 is incident on a surface perpendicular to the beam. The number of photons crossing 1cm2 area perpendicular to the beam in one second is :
[26-Jul-2022-Shift-1]
Q.70 Correct
Q.70 In-correct
Q.70 Unattempt
With reference to the observations in photo-electric effect, identify the correct statements from below
(A) The square of maximum velocity of photoelectrons varies linearly with frequency of incident light.
(B) The value of saturation current increases on moving the source of light away from the metal surface.
(C) The maximum kinetic energy of photo-electrons decreases on decreasing the power of LED (light emitting diode) source of light.
(D) The immediate emission of photo-electrons out of metal surface can not be explained by particle nature of light/electromagnetic waves.
(E) Existence of threshold wavelength can not be explained by wave nature of light / electromagnetic waves.
Choose the correct answer from the options given below :
[27-Jul-2022-Shift-2]
With reference to the observations in photo-electric effect, identify the correct statements from below
(A) The square of maximum velocity of photoelectrons varies linearly with frequency of incident light.
(B) The value of saturation current increases on moving the source of light away from the metal surface.
(C) The maximum kinetic energy of photo-electrons decreases on decreasing the power of LED (light emitting diode) source of light.
(D) The immediate emission of photo-electrons out of metal surface can not be explained by particle nature of light/electromagnetic waves.
(E) Existence of threshold wavelength can not be explained by wave nature of light / electromagnetic waves.
Choose the correct answer from the options given below :
[27-Jul-2022-Shift-2]
Q.71 Correct
Q.71 In-correct
Q.71 Unattempt
The equation λ=‌
1.227
x
‌nm can be used to find the de-Brogli wavelength of an electron. In this equation x stands for:
Where
m= mass of electron
P− momentum of electron
K= Kinetic energy of electron
V= Accelerating potential in volts for electron
[28-Jul-2022-Shift-1]
The equation λ=‌
1.227
x
‌nm can be used to find the de-Brogli wavelength of an electron. In this equation x stands for:
Where
m= mass of electron
P− momentum of electron
K= Kinetic energy of electron
V= Accelerating potential in volts for electron
[28-Jul-2022-Shift-1]
Q.72 Correct
Q.72 In-correct
Q.72 Unattempt
Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface successively. The ratio of maximum velocities of the photoelectron emitted, in the two cases respectively, will be
[28-Jul-2022-Shift-2]
Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface successively. The ratio of maximum velocities of the photoelectron emitted, in the two cases respectively, will be
[28-Jul-2022-Shift-2]
Q.73 Correct
Q.73 In-correct
Q.73 Unattempt
The kinetic energy of emitted electron is E when the light incident on the metal has wavelength λ. To double the kinetic energy, the incident light must have wavelength:
[29-Jul-2022-Shift-1]
The kinetic energy of emitted electron is E when the light incident on the metal has wavelength λ. To double the kinetic energy, the incident light must have wavelength:
[29-Jul-2022-Shift-1]
Q.74 Correct
Q.74 In-correct
Q.74 Unattempt
An α particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two particles will be:
[29-Jul-2022-Shift-2]
An α particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two particles will be:
[29-Jul-2022-Shift-2]
Q.75 Correct
Q.75 In-correct
Q.75 Unattempt
Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective cases is x:y. The value of x is .............. .
[26 Feb 2021 Shift 2]
Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective cases is x:y. The value of x is .............. .
[26 Feb 2021 Shift 2]
Q.76 Correct
Q.76 In-correct
Q.76 Unattempt
The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491nm is 0.710V. When the incident wavelength is changed to a new value, the stopping potential is 1.43V. The new wavelength is
[25 Feb 2021 Shift 2]
The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491nm is 0.710V. When the incident wavelength is changed to a new value, the stopping potential is 1.43V. The new wavelength is
[25 Feb 2021 Shift 2]
Q.77 Correct
Q.77 In-correct
Q.77 Unattempt
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A An electron microscope can achieve better resolving power than an optical microscope.
Reason R The de-Broglie's wavelength of theelectrons emitted from an electron gun is much less than wavelength of visible light.
In the light of the above statements, choose the correct answer from the options given below.
[26 Feb 2021 Shift 1]
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A An electron microscope can achieve better resolving power than an optical microscope.
Reason R The de-Broglie's wavelength of theelectrons emitted from an electron gun is much less than wavelength of visible light.
In the light of the above statements, choose the correct answer from the options given below.
[26 Feb 2021 Shift 1]
Q.78 Correct
Q.78 In-correct
Q.78 Unattempt
The wavelength of an X-ray beam is 10Å. The mass of a fictitious particle having the same energy as that of the X-ray photons is ‌
x
3
hkg. The value of x is ............
( h = Planck's constant)
[25 Feb 2021 Shift 2]
The wavelength of an X-ray beam is 10Å. The mass of a fictitious particle having the same energy as that of the X-ray photons is ‌
x
3
hkg. The value of x is ............
( h = Planck's constant)
[25 Feb 2021 Shift 2]
Q.79 Correct
Q.79 In-correct
Q.79 Unattempt
An electron of mass me and a proton of mass mp=1836me are moving with the same speed. The ratio of their de-Broglie wavelength ‌
λ‌electron ‌
λ‌proton ‌
 will be
[25 Feb 2021 Shift 2]
An electron of mass me and a proton of mass mp=1836me are moving with the same speed. The ratio of their de-Broglie wavelength ‌
λ‌electron ‌
λ‌proton ‌
 will be
[25 Feb 2021 Shift 2]
Q.80 Correct
Q.80 In-correct
Q.80 Unattempt
A proton, a deuteron and an α-particle are moving with same momentum in a uniform magnetic field. The ratio of magnetic forces acting on them is ......... and their speed is ......... in the ratio.
[25 Feb 2021 Shift 1]
A proton, a deuteron and an α-particle are moving with same momentum in a uniform magnetic field. The ratio of magnetic forces acting on them is ......... and their speed is ......... in the ratio.
[25 Feb 2021 Shift 1]
Q.81 Correct
Q.81 In-correct
Q.81 Unattempt
The de-Broglie wavelength of a proton and α-particle are equal. The ratio of their velocities is
[24 Feb 2021 Shift 2]
The de-Broglie wavelength of a proton and α-particle are equal. The ratio of their velocities is
[24 Feb 2021 Shift 2]
Q.82 Correct
Q.82 In-correct
Q.82 Unattempt
An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be
[24 Feb 2021 Shift 2]
An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be
[24 Feb 2021 Shift 2]
Q.83 Correct
Q.83 In-correct
Q.83 Unattempt
Given below are two statements :
Statement-I : Two photons having equal linear momenta have equal wavelengths.
Statement-II: If the wavelength of photon is decreased, then the momentum and energy of a photon will also decrease.
In the light of the above statements, choose the correct answer from the options given below.
[24feb2021shift1]
Given below are two statements :
Statement-I : Two photons having equal linear momenta have equal wavelengths.
Statement-II: If the wavelength of photon is decreased, then the momentum and energy of a photon will also decrease.
In the light of the above statements, choose the correct answer from the options given below.
[24feb2021shift1]
Q.84 Correct
Q.84 In-correct
Q.84 Unattempt
Two identical photocathodes receive the light of frequencies f1 and f2, respectively. If the velocities of the photoelectrons coming out are v1 and v2 respectively, then
[17 Mar 2021 Shift 2]
Two identical photocathodes receive the light of frequencies f1 and f2, respectively. If the velocities of the photoelectrons coming out are v1 and v2 respectively, then
[17 Mar 2021 Shift 2]
Q.85 Correct
Q.85 In-correct
Q.85 Unattempt
The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation
[16 Mar 2021 Shift 1]
The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation
[16 Mar 2021 Shift 1]
Q.86 Correct
Q.86 In-correct
Q.86 Unattempt
If 2.5×10−6N average force is exerted by a light wave on a non-reflecting surface of 30cm2 area during 40 min of time span, the energy flux of light just before it falls on the surface is ......W \/ cm2.
(Round off to the nearest integer. Assume complete absorption and normal incidence conditions are there.)
[17 Mar 2021 Shift 1]
If 2.5×10−6N average force is exerted by a light wave on a non-reflecting surface of 30cm2 area during 40 min of time span, the energy flux of light just before it falls on the surface is ......W \/ cm2.
(Round off to the nearest integer. Assume complete absorption and normal incidence conditions are there.)
[17 Mar 2021 Shift 1]
Q.87 Correct
Q.87 In-correct
Q.87 Unattempt
The speed of electrons in a scanning electron microscope is 1×107ms−1. If the protons having the same speed are used instead of electrons, then the resolving power of scanning proton microscope will be changed by a factor of
[18 Mar 2021 Shift 2]
The speed of electrons in a scanning electron microscope is 1×107ms−1. If the protons having the same speed are used instead of electrons, then the resolving power of scanning proton microscope will be changed by a factor of
[18 Mar 2021 Shift 2]
Q.88 Correct
Q.88 In-correct
Q.88 Unattempt
A particle is travelling 4 times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2:1, the mass of the particle is
[18 Mar 2021 Shift 1]
A particle is travelling 4 times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2:1, the mass of the particle is
[18 Mar 2021 Shift 1]
Q.89 Correct
Q.89 In-correct
Q.89 Unattempt
An electron of mass m and a photon have same energy E. The ratio of wavelength of electron to that of photon is (c being the velocity of light)
[17 Mar 2021 Shift 1]
An electron of mass m and a photon have same energy E. The ratio of wavelength of electron to that of photon is (c being the velocity of light)
[17 Mar 2021 Shift 1]
Q.90 Correct
Q.90 In-correct
Q.90 Unattempt
The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100V. What should nearly be the ratio of their wavelengths? (mp=1.00727u, me=0.00055u )
[16 Mar 2021 Shift 2]
The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100V. What should nearly be the ratio of their wavelengths? (mp=1.00727u, me=0.00055u )
[16 Mar 2021 Shift 2]
Q.91 Correct
Q.91 In-correct
Q.91 Unattempt
A light beam of wavelength 500nm is incident on a metal having work function of 1.25eV, placed in a magnetic field of intensity B. The electrons emitted perpendicular to the magnetic field B, with maximum kinetic energy are bent into circular arc of radius 30cm. The value of B is _______ ×10−7T
Given hc=20×10−26J−m, mass of electron=9×10−31kg
[25 Jul 2021 Shift 2]
A light beam of wavelength 500nm is incident on a metal having work function of 1.25eV, placed in a magnetic field of intensity B. The electrons emitted perpendicular to the magnetic field B, with maximum kinetic energy are bent into circular arc of radius 30cm. The value of B is _______ ×10−7T
Given hc=20×10−26J−m, mass of electron=9×10−31kg
[25 Jul 2021 Shift 2]
Q.92 Correct
Q.92 In-correct
Q.92 Unattempt
When radiation of wavelength λ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8V. If the same surface is illuminated by radiation of double the previous wavelength, then the stopping potential becomes 1.6V. The threshold wavelength of the metal is :
[25 Jul 2021 Shift 2]
When radiation of wavelength λ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8V. If the same surface is illuminated by radiation of double the previous wavelength, then the stopping potential becomes 1.6V. The threshold wavelength of the metal is :
[25 Jul 2021 Shift 2]
Q.93 Correct
Q.93 In-correct
Q.93 Unattempt
A certain metallic surface is illuminated by monochromatic radiation of wavelength λ. The stopping potential for photoelectric current for this radiation is 3V0. If the same surface is illuminated with a radiation of wavelength 2λ, the stopping potential is V0. The threshold wavelength of this surface for photoelectric effect is________ λ.
[20 Jul 2021 Shift 2]
A certain metallic surface is illuminated by monochromatic radiation of wavelength λ. The stopping potential for photoelectric current for this radiation is 3V0. If the same surface is illuminated with a radiation of wavelength 2λ, the stopping potential is V0. The threshold wavelength of this surface for photoelectric effect is________ λ.
[20 Jul 2021 Shift 2]
Q.94 Correct
Q.94 In-correct
Q.94 Unattempt
A particle of mass 9.1×10−31kg travels in a medium with a speed of 106m∕s and a photon of aradiation of linear momentum 10−27kgm∕s travelsin vacuum. The wavelength of photon is _______ times the wavelength of the particle.
[27 Jul 2021 Shift 1]
A particle of mass 9.1×10−31kg travels in a medium with a speed of 106m∕s and a photon of aradiation of linear momentum 10−27kgm∕s travelsin vacuum. The wavelength of photon is _______ times the wavelength of the particle.
[27 Jul 2021 Shift 1]
Q.95 Correct
Q.95 In-correct
Q.95 Unattempt
An electron moving with speed v and a photon moving with speed c, have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of photon is :
[25 Jul 2021 Shift 2]
An electron moving with speed v and a photon moving with speed c, have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of photon is :
[25 Jul 2021 Shift 2]
Q.96 Correct
Q.96 In-correct
Q.96 Unattempt
An electron of mass me and a proton of mass mP are accelerated through the same potential difference. The ratio of the de-Broglie wavelength associated with the electron to that with the proton is :-
[22 Jul 2021 Shift 2]
An electron of mass me and a proton of mass mP are accelerated through the same potential difference. The ratio of the de-Broglie wavelength associated with the electron to that with the proton is :-
[22 Jul 2021 Shift 2]
Q.97 Correct
Q.97 In-correct
Q.97 Unattempt
An electron having de-Broglie wavelength λ is incident on a target in a X-ray tube. Cut-off wavelength of emitted X-ray is :
[20 Jul 2021 Shift 2]
An electron having de-Broglie wavelength λ is incident on a target in a X-ray tube. Cut-off wavelength of emitted X-ray is :
[20 Jul 2021 Shift 2]
Q.98 Correct
Q.98 In-correct
Q.98 Unattempt
In a photoelectric experiment, increasing the intensity of incident light
[27 Aug 2021 Shift 1]
In a photoelectric experiment, increasing the intensity of incident light
[27 Aug 2021 Shift 1]
Q.99 Correct
Q.99 In-correct
Q.99 Unattempt
A monochromatic neon lamp with wavelength of 670.5‌nm illuminates a photo-sensitive material which has a stopping voltage of 0.48V. What will be the stopping voltage if the source light is changed with another source of wavelength of 474.6‌nm ?
[27 Aug 2021 Shift 2]
A monochromatic neon lamp with wavelength of 670.5‌nm illuminates a photo-sensitive material which has a stopping voltage of 0.48V. What will be the stopping voltage if the source light is changed with another source of wavelength of 474.6‌nm ?
[27 Aug 2021 Shift 2]
Q.100 Correct
Q.100 In-correct
Q.100 Unattempt
In a photoelectric experiment ultraviolet light of wavelength 280‌nm is used with lithium cathode having work - function ϕ=2.5‌eV. If the wavelength of incident light is switched to 400‌nm, find out the change in the stopping potential. (h=6.63×10−34‌Js., and c=3×108ms−1 )
[26 Aug 2021 Shift 1]
In a photoelectric experiment ultraviolet light of wavelength 280‌nm is used with lithium cathode having work - function ϕ=2.5‌eV. If the wavelength of incident light is switched to 400‌nm, find out the change in the stopping potential. (h=6.63×10−34‌Js., and c=3×108ms−1 )
[26 Aug 2021 Shift 1]
Q.101 Correct
Q.101 In-correct
Q.101 Unattempt
Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is proportional to
[31 Aug 2021 Shift 2]
Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is proportional to
[31 Aug 2021 Shift 2]
Q.102 Correct
Q.102 In-correct
Q.102 Unattempt
A moving proton and electron have the same de-Broglie wavelength. If k and p denote the KE and momentum, respectively. Then, choose the correct option.
[31 Aug 2021 Shift 1]
A moving proton and electron have the same de-Broglie wavelength. If k and p denote the KE and momentum, respectively. Then, choose the correct option.
[31 Aug 2021 Shift 1]
Q.103 Correct
Q.103 In-correct
Q.103 Unattempt
The de-Broglie wavelength of a particle having kinetic energy E is λ. How much extra energy must be given to this particle, so that the de-Broglie wavelength reduces to 75% of the initial value ?
[26 Aug 2021 Shift 2]
The de-Broglie wavelength of a particle having kinetic energy E is λ. How much extra energy must be given to this particle, so that the de-Broglie wavelength reduces to 75% of the initial value ?
[26 Aug 2021 Shift 2]
Q.104 Correct
Q.104 In-correct
Q.104 Unattempt
The temperature of an ideal gas in 3 - dimensions is 300K. The corresponding de-Broglie wavelength of the electron approximately at 300K, is
[me= mass of electron =9×10−31‌kg
h= Planck's constant =6.6×10−34‌Js
KB= Boltzmann constant =1.38×10−23JK−1]
[1 Sep 2021 Shift 2]
The temperature of an ideal gas in 3 - dimensions is 300K. The corresponding de-Broglie wavelength of the electron approximately at 300K, is
[me= mass of electron =9×10−31‌kg
h= Planck's constant =6.6×10−34‌Js
KB= Boltzmann constant =1.38×10−23JK−1]
[1 Sep 2021 Shift 2]
Q.105 Correct
Q.105 In-correct
Q.105 Unattempt
A particle moving with kinetic energy E has de Broglie wavelength λ. If energy ΔE is added to its energy, the wavelength become
λ
2
. Value of ΔE, is:
[9 Jan. 2020 I]
A particle moving with kinetic energy E has de Broglie wavelength λ. If energy ΔE is added to its energy, the wavelength become
λ
2
. Value of ΔE, is:
[9 Jan. 2020 I]
Q.106 Correct
Q.106 In-correct
Q.106 Unattempt
An electron of mass m and magnitude of charge |e| initially at rest gets accelerated by a constant electric field E. The rate of change of de-Broglie wavelength of this electron at time t ignoring relativistic effects is:
[9 Jan. 2020 II]
An electron of mass m and magnitude of charge |e| initially at rest gets accelerated by a constant electric field E. The rate of change of de-Broglie wavelength of this electron at time t ignoring relativistic effects is:
[9 Jan. 2020 II]
Q.107 Correct
Q.107 In-correct
Q.107 Unattempt
An electron (mass m ) with initial velocity
→
v
=v0
^
i
+v0
^
j
 is in an electric field
→
E
=−E0
^
k
. If λ0 is initial de-Broglie wavelength of electron, its de-Broglie wave length at time t is given by:
[8 Jan. 2020 II]
An electron (mass m ) with initial velocity
→
v
=v0
^
i
+v0
^
j
 is in an electric field
→
E
=−E0
^
k
. If λ0 is initial de-Broglie wavelength of electron, its de-Broglie wave length at time t is given by:
[8 Jan. 2020 II]
Q.108 Correct
Q.108 In-correct
Q.108 Unattempt
A beam of electrons of energy E scatters from a target having atomic spacing of 1Å. The first maximum intensity occurs at θ=60°. Then E( in eV) is ______.
(Plank constant h=6.64×10−34Js,1eV=1.6×10−19J,
electron mass m=9.1×10−31kg)
[NA Sep. 05, 2020 (I)]
A beam of electrons of energy E scatters from a target having atomic spacing of 1Å. The first maximum intensity occurs at θ=60°. Then E( in eV) is ______.
(Plank constant h=6.64×10−34Js,1eV=1.6×10−19J,
electron mass m=9.1×10−31kg)
[NA Sep. 05, 2020 (I)]
Q.109 Correct
Q.109 In-correct
Q.109 Unattempt
Radiation, with wavelength 6561 Å falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3×10–4 T. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to:
[9 Jan. 2020 I]
Radiation, with wavelength 6561 Å falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3×10–4 T. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to:
[9 Jan. 2020 I]
Q.110 Correct
Q.110 In-correct
Q.110 Unattempt
When photon of energy 4.0eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy TAeV and de-Broglie wavelength λA. The maximum kinetic energy of photoelectrons liberated from another metal B by photon of energy 4.50eV is TB=(TA−1.5)eV. If the de-Broglie wavelength of these photoelectrons λB= 2λA, then the work function of metal B is:
[8 Jan. 2020 I]
When photon of energy 4.0eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy TAeV and de-Broglie wavelength λA. The maximum kinetic energy of photoelectrons liberated from another metal B by photon of energy 4.50eV is TB=(TA−1.5)eV. If the de-Broglie wavelength of these photoelectrons λB= 2λA, then the work function of metal B is:
[8 Jan. 2020 I]
Q.111 Correct
Q.111 In-correct
Q.111 Unattempt
A beam of electromagnetic radiation of intensity 6.4×10−5W∕cm2 is comprised of wavelength, λ=310 nm. It falls normally on a metal (work function φ=2eV ) of surface area of 1cm2. If one in 103 photons ejects an electron, total number of electrons ejected in 1s is 10x. (hc=1240eVnm,1eV=1.6×10−19J), then x is ______.
[NA 7 Jan. 2020 I]
A beam of electromagnetic radiation of intensity 6.4×10−5W∕cm2 is comprised of wavelength, λ=310 nm. It falls normally on a metal (work function φ=2eV ) of surface area of 1cm2. If one in 103 photons ejects an electron, total number of electrons ejected in 1s is 10x. (hc=1240eVnm,1eV=1.6×10−19J), then x is ______.
[NA 7 Jan. 2020 I]
Q.112 Correct
Q.112 In-correct
Q.112 Unattempt
An electron, a doubly ionized helium ion (He++) and a proton are having the same kinetic energy. The relation between their respective de-Broglie wavelengths λe,λHe++ and λp is
[Sep. 06, 2020 (I)]
An electron, a doubly ionized helium ion (He++) and a proton are having the same kinetic energy. The relation between their respective de-Broglie wavelengths λe,λHe++ and λp is
[Sep. 06, 2020 (I)]
Q.113 Correct
Q.113 In-correct
Q.113 Unattempt
Assuming the nitrogen molecule is moving with r.m.s.velocity at 400 K, the de-Broglie wavelength of nitrongen molecule is close to :
(Given : nitrogen molecule weight : 4.64×10–26 kg, Boltzman constant : 1.38×10–23 J/K, Planck constant : 6.63×10–34 J.s)
[Sep. 06, 2020 (II)]
Assuming the nitrogen molecule is moving with r.m.s.velocity at 400 K, the de-Broglie wavelength of nitrongen molecule is close to :
(Given : nitrogen molecule weight : 4.64×10–26 kg, Boltzman constant : 1.38×10–23 J/K, Planck constant : 6.63×10–34 J.s)
[Sep. 06, 2020 (II)]
Q.114 Correct
Q.114 In-correct
Q.114 Unattempt
Particle A of mass mA=
m
2
 moving along the x -axis with velocity v0 collides elastically with another particle B at rest having mass mB=
m
3
. If both particles move along the x -axis after the collision, the change Δλ in de-Broglie wavelength of particle A, in terms of its de-Broglie wavelength (λ0) before collision is :
[Sep. 04, 2020 (I)]
Particle A of mass mA=
m
2
 moving along the x -axis with velocity v0 collides elastically with another particle B at rest having mass mB=
m
3
. If both particles move along the x -axis after the collision, the change Δλ in de-Broglie wavelength of particle A, in terms of its de-Broglie wavelength (λ0) before collision is :
[Sep. 04, 2020 (I)]
Q.115 Correct
Q.115 In-correct
Q.115 Unattempt
A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is 1.878×10−4. The mass of the particle is close to :
[Sep. 02, 2020 (II)]
A particle is moving 5 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is 1.878×10−4. The mass of the particle is close to :
[Sep. 02, 2020 (II)]
Q.116 Correct
Q.116 In-correct
Q.116 Unattempt
The surface of a metal is illuminated alternately with photons of energies E1=4 eV and E2=2.5 eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2. The work function of the metal in (eV) is ________.
[NA Sep. 05, 2020 (II)]
The surface of a metal is illuminated alternately with photons of energies E1=4 eV and E2=2.5 eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2. The work function of the metal in (eV) is ________.
[NA Sep. 05, 2020 (II)]
Q.117 Correct
Q.117 In-correct
Q.117 Unattempt
Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surface is : (Plancks constant h=6.62×10–34 J.s)

[Sep. 04, 2020 (I)]
Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surface is : (Plancks constant h=6.62×10–34 J.s)

[Sep. 04, 2020 (I)]
Q.118 Correct
Q.118 In-correct
Q.118 Unattempt
In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased :

[Sep. 04, 2020 (II)]
In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased :

[Sep. 04, 2020 (II)]
Q.119 Correct
Q.119 In-correct
Q.119 Unattempt
When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :
[Sep. 03, 2020 (I)]
When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to :
[Sep. 03, 2020 (I)]
Q.120 Correct
Q.120 In-correct
Q.120 Unattempt
Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the sources emit light of the same power 200 W. The ratio of the number density of photons of X-rays to the number density of photons of the visible light of the given wavelengths is :
[Sep. 03, 2020 (II)]
Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the sources emit light of the same power 200 W. The ratio of the number density of photons of X-rays to the number density of photons of the visible light of the given wavelengths is :
[Sep. 03, 2020 (II)]
Q.121 Correct
Q.121 In-correct
Q.121 Unattempt
When radiation of wavelength λ is used to illuminate a metallic surface, the stopping potential is V. When the same surface is illuminated with radiation of wavelength 3λ , the stopping potential is .
V
4
 . If the threshold wavelength for the metallic surface is nl then value of nλ will be _________.
[NA Sep. 02, 2020 (I)]
When radiation of wavelength λ is used to illuminate a metallic surface, the stopping potential is V. When the same surface is illuminated with radiation of wavelength 3λ , the stopping potential is .
V
4
 . If the threshold wavelength for the metallic surface is nl then value of nλ will be _________.
[NA Sep. 02, 2020 (I)]
Q.122 Correct
Q.122 In-correct
Q.122 Unattempt
A particle A of mass 'm' and charge 'q' is accelerated by a potential difference of 50v Another particle B of mass 4m ' and charge'q is accelerated by a potential differnce of2500V. The ratio of de-Broglie wavelength
λA
λB
 is
[12 Jan. 2019 I]
A particle A of mass 'm' and charge 'q' is accelerated by a potential difference of 50v Another particle B of mass 4m ' and charge'q is accelerated by a potential differnce of2500V. The ratio of de-Broglie wavelength
λA
λB
 is
[12 Jan. 2019 I]
Q.123 Correct
Q.123 In-correct
Q.123 Unattempt
If the deBroglie wavelength of an electron is equal to 10−3 times the wavelength of a photon of frequency 6×1014 Hz, then the speed of electron is equal to :
(Speed of light =3×108m∕s)
Planck's constant =6.63×10−34J.s
Mass of electron =9.1×10−31kg )
[11 Jan. 2019 I]
If the deBroglie wavelength of an electron is equal to 10−3 times the wavelength of a photon of frequency 6×1014 Hz, then the speed of electron is equal to :
(Speed of light =3×108m∕s)
Planck's constant =6.63×10−34J.s
Mass of electron =9.1×10−31kg )
[11 Jan. 2019 I]
Q.124 Correct
Q.124 In-correct
Q.124 Unattempt
In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5×10−12 m, the minimum electron energy required is close to:
[10 Jan. 2019 I]
In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5×10−12 m, the minimum electron energy required is close to:
[10 Jan. 2019 I]
Q.125 Correct
Q.125 In-correct
Q.125 Unattempt
When a certain photosensistive surface is illuminated with monochromatic light of frequency v, the stopping potential for the photo current is −V0∕2. When the surface is illuminated by monochromatic light of frequency v∕2, the stoppoing potential is −V0. The threshold frequency for photoelectric emission is:
[12 Jan. 2019 II]
When a certain photosensistive surface is illuminated with monochromatic light of frequency v, the stopping potential for the photo current is −V0∕2. When the surface is illuminated by monochromatic light of frequency v∕2, the stoppoing potential is −V0. The threshold frequency for photoelectric emission is:
[12 Jan. 2019 II]
Q.126 Correct
Q.126 In-correct
Q.126 Unattempt
In a Frank-Hertz experiment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7 eV. The minimum wavelength of photons emitted by mercury atoms is close to :
[12 Jan. 2019 II]
In a Frank-Hertz experiment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7 eV. The minimum wavelength of photons emitted by mercury atoms is close to :
[12 Jan. 2019 II]
Q.127 Correct
Q.127 In-correct
Q.127 Unattempt
In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300 nm to 400 nm. The decrease in the stopping potential is close to :
(
hc
e
=1240nm−V)
[11 Jan. 2019 II]
In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300 nm to 400 nm. The decrease in the stopping potential is close to :
(
hc
e
=1240nm−V)
[11 Jan. 2019 II]
Q.128 Correct
Q.128 In-correct
Q.128 Unattempt
A metal plate of area 1×10−4m2 is illuminated by a radiation of intensity 16mW∕m2. The work function of the metal is 5eV. The energy of the incident photons is 10eV and only 10% of it produces photo electrons. The number of emitted photo electrons per second and their maximum energy, respectively, will be:
[1eV=1.6×10−19J]
[10 Jan. 2019 II]
A metal plate of area 1×10−4m2 is illuminated by a radiation of intensity 16mW∕m2. The work function of the metal is 5eV. The energy of the incident photons is 10eV and only 10% of it produces photo electrons. The number of emitted photo electrons per second and their maximum energy, respectively, will be:
[1eV=1.6×10−19J]
[10 Jan. 2019 II]
Q.129 Correct
Q.129 In-correct
Q.129 Unattempt
Surface of certain metal is first illuminated with light of wavelength λ1=350 nm and then, by light of wavelength λ2=540 nm. It is found that the maximum speed of the photo electrons in the two cases differ by a factor of (2)The work function of the metal (in eV) is close to:
(Energy of photon =
1240
λ( in nm)
eV )
[9 Jan. 2019 I]
Surface of certain metal is first illuminated with light of wavelength λ1=350 nm and then, by light of wavelength λ2=540 nm. It is found that the maximum speed of the photo electrons in the two cases differ by a factor of (2)The work function of the metal (in eV) is close to:
(Energy of photon =
1240
λ( in nm)
eV )
[9 Jan. 2019 I]
Q.130 Correct
Q.130 In-correct
Q.130 Unattempt
The magnetic field associated with a light wave is given at the origin by
B=B0[sin(3.14×107)‌ct +sin(6.28×107)‌ct]
If this light falls on a silver plate having a work function of 4.7 eV, what will be the maximum kinetic energy of thephotoelectrons?
(c=3×108ms−1,h=6.6×10−34J−s)
[9 Jan. 2019 II]
The magnetic field associated with a light wave is given at the origin by
B=B0[sin(3.14×107)‌ct +sin(6.28×107)‌ct]
If this light falls on a silver plate having a work function of 4.7 eV, what will be the maximum kinetic energy of thephotoelectrons?
(c=3×108ms−1,h=6.6×10−34J−s)
[9 Jan. 2019 II]
Q.131 Correct
Q.131 In-correct
Q.131 Unattempt
A particle ' P ' is formed due to a completely inelastic collision of particles ' x ' and ' y ' having de-Broglie wavelengths ′λx′ and ′λy ' respectively. If x and y were moving in opposite directions, then the de-Broglie wavelength of ' P ' is:
[9 Apr. 2019 II]
A particle ' P ' is formed due to a completely inelastic collision of particles ' x ' and ' y ' having de-Broglie wavelengths ′λx′ and ′λy ' respectively. If x and y were moving in opposite directions, then the de-Broglie wavelength of ' P ' is:
[9 Apr. 2019 II]
Q.132 Correct
Q.132 In-correct
Q.132 Unattempt
Two particles move at right angle to each other. Their de Broglie wavelengths are λ1 and λ2 respectively. The particles suffer perfectly inelastic collision. The de Broglie wavelength λ, of the final particle, is given by:
[8 April 2019 I]
Two particles move at right angle to each other. Their de Broglie wavelengths are λ1 and λ2 respectively. The particles suffer perfectly inelastic collision. The de Broglie wavelength λ, of the final particle, is given by:
[8 April 2019 I]
Q.133 Correct
Q.133 In-correct
Q.133 Unattempt
The stopping potential V0 (in volt) as a function of frequency(v) for a sodium emitter, is shown in the figure. The work function of sodium, from the data plotted in the figure, will be: (Given : Planck's constant (h)=6.63×10−34Js, electron charge e=1.6×10−19C)

[12 Apr. 2019 I]
The stopping potential V0 (in volt) as a function of frequency(v) for a sodium emitter, is shown in the figure. The work function of sodium, from the data plotted in the figure, will be: (Given : Planck's constant (h)=6.63×10−34Js, electron charge e=1.6×10−19C)

[12 Apr. 2019 I]
Q.134 Correct
Q.134 In-correct
Q.134 Unattempt
In a photoelectric effect experiment the threshold wavelength of light is 380 nm. If the wavelength of incident light is 260 nm, the maximum kinetic energy of emitted electrons will be:
Given E (in eV) =
[10 Apr. 2019 I]
In a photoelectric effect experiment the threshold wavelength of light is 380 nm. If the wavelength of incident light is 260 nm, the maximum kinetic energy of emitted electrons will be:
Given E (in eV) =
[10 Apr. 2019 I]
Q.135 Correct
Q.135 In-correct
Q.135 Unattempt
A 2mW laser operates at a wavelength of 500nm. The number of photons that will be emitted per second is :
[Given Planck's constant h=6.6×10−34Js, speed of light c=3.0×108m∕s]
[10 Apr. 2019 II]
A 2mW laser operates at a wavelength of 500nm. The number of photons that will be emitted per second is :
[Given Planck's constant h=6.6×10−34Js, speed of light c=3.0×108m∕s]
[10 Apr. 2019 II]
Q.136 Correct
Q.136 In-correct
Q.136 Unattempt
The electric field of light wave is given as
→
E
=103‌cos(
2πx
5×10−7
−2π×6×1014t)
^
x
N
C
This light falls on a metal plate of work function 2eV. The stopping potential of the photo-electrons is:
Given, E( in eV)=
12375
λ( in Å)
[9 April 2019 I]
The electric field of light wave is given as
→
E
=103‌cos(
2πx
5×10−7
−2π×6×1014t)
^
x
N
C
This light falls on a metal plate of work function 2eV. The stopping potential of the photo-electrons is:
Given, E( in eV)=
12375
λ( in Å)
[9 April 2019 I]
Q.137 Correct
Q.137 In-correct
Q.137 Unattempt
Two electrons are moving with non-relativistic speeds perpendicular to each other. If corresponding de Broglie wavelengths are λ1 and λ2, their de Broglie wavelength in the frame of reference attached to their centre of mass is:
[Online April 15, 2018]
Two electrons are moving with non-relativistic speeds perpendicular to each other. If corresponding de Broglie wavelengths are λ1 and λ2, their de Broglie wavelength in the frame of reference attached to their centre of mass is:
[Online April 15, 2018]
Q.138 Correct
Q.138 In-correct
Q.138 Unattempt
If the de Broglie wavelengths associated with a proton and an α-particle are equal, then the ratio of velocities of the proton and the α-particle will be:
[Online April 15, 2018]
If the de Broglie wavelengths associated with a proton and an α-particle are equal, then the ratio of velocities of the proton and the α-particle will be:
[Online April 15, 2018]
Q.139 Correct
Q.139 In-correct
Q.139 Unattempt
A particle A of mass m and initial velocity v collides with a particle B of mass
m
2
 which is at rest. The collision is head on, and elastic. The ratio of the de-Broglie wavelengths λA to λB after the collision is
[2017]
A particle A of mass m and initial velocity v collides with a particle B of mass
m
2
 which is at rest. The collision is head on, and elastic. The ratio of the de-Broglie wavelengths λA to λB after the collision is
[2017]
Q.140 Correct
Q.140 In-correct
Q.140 Unattempt
An electron beam is accelerated by a potential difference V to hit a metallic target to produce X-rays. It produces continuous as well as characteristic X-rays.If λmin is the smallest possible wavelength of X -ray in the spectrum, the variation of log‌λmin with log‌V is correctly represented in :
[2017]
An electron beam is accelerated by a potential difference V to hit a metallic target to produce X-rays. It produces continuous as well as characteristic X-rays.If λmin is the smallest possible wavelength of X -ray in the spectrum, the variation of log‌λmin with log‌V is correctly represented in :
[2017]
Q.141 Correct
Q.141 In-correct
Q.141 Unattempt
A Laser light of wavelength 660nm is used to weld Retina detachment. If a Laser pulse of width 60ms and power 0.5 kW is used the approximate number of photons in the pulse are : [Take Planck's constant h=6.62×10−34Js]
[Online April 9, 2017]
A Laser light of wavelength 660nm is used to weld Retina detachment. If a Laser pulse of width 60ms and power 0.5 kW is used the approximate number of photons in the pulse are : [Take Planck's constant h=6.62×10−34Js]
[Online April 9, 2017]
Q.142 Correct
Q.142 In-correct
Q.142 Unattempt
The maximum velocity of the photoelectrons emitted from the surface is v when light of frequency n falls on a metal surface. If the incident frequency is increased to 3n, the maximum velocity of the ejected photoelectrons will be :
[Online April 8, 2017]
The maximum velocity of the photoelectrons emitted from the surface is v when light of frequency n falls on a metal surface. If the incident frequency is increased to 3n, the maximum velocity of the ejected photoelectrons will be :
[Online April 8, 2017]
Q.143 Correct
Q.143 In-correct
Q.143 Unattempt
Radiation of wavelength lambda, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to
3λ
4
, the speed of the fastest emitted electron will be:
[2016]
Radiation of wavelength lambda, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to
3λ
4
, the speed of the fastest emitted electron will be:
[2016]
Q.144 Correct
Q.144 In-correct
Q.144 Unattempt
A photoelectric surface is illuminated successively by monochromatic light of wavelengths λ and
λ
2
. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface is :
[Online April 10,2016]
A photoelectric surface is illuminated successively by monochromatic light of wavelengths λ and
λ
2
. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface is :
[Online April 10,2016]
Q.145 Correct
Q.145 In-correct
Q.145 Unattempt
When photons of wavelength λ1 are incident on an isolated sphere, the corresponding stopping potential is found to be V. When photons of wavelength λ2 are used, the corresponding stopping potential was thrice that of the above value. If light of wavelength λ3 is used then find the stopping potential for this case :
[Online April 9,2016]
When photons of wavelength λ1 are incident on an isolated sphere, the corresponding stopping potential is found to be V. When photons of wavelength λ2 are used, the corresponding stopping potential was thrice that of the above value. If light of wavelength λ3 is used then find the stopping potential for this case :
[Online April 9,2016]
Q.146 Correct
Q.146 In-correct
Q.146 Unattempt
A parallel beam of electrons travelling in x-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum py in the y-direction then for a majority of electrons passing through the slit (h is Planck’s constant) :

[Online April 10, 2015]
A parallel beam of electrons travelling in x-direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum py in the y-direction then for a majority of electrons passing through the slit (h is Planck’s constant) :

[Online April 10, 2015]
Q.147 Correct
Q.147 In-correct
Q.147 Unattempt
de-Broglie wavelength of an electron accelerated by a voltage of 50V is close to (|e|=1.6×10−19C,me=9.1×10−31kg h=6.6×10−34Js):
[Online April 10, 2015]
de-Broglie wavelength of an electron accelerated by a voltage of 50V is close to (|e|=1.6×10−19C,me=9.1×10−31kg h=6.6×10−34Js):
[Online April 10, 2015]
Q.148 Correct
Q.148 In-correct
Q.148 Unattempt
For which of the following particles will it be most difficult to experimentally verify the de-Broglie relationship?
[Online April 9, 2015]
For which of the following particles will it be most difficult to experimentally verify the de-Broglie relationship?
[Online April 9, 2015]
Q.149 Correct
Q.149 In-correct
Q.149 Unattempt
Match List - I (Fundamental Experiment) with List - II (its conclusion) and select the correct option from the choices given below the list:

[2015]
Match List - I (Fundamental Experiment) with List - II (its conclusion) and select the correct option from the choices given below the list:

[2015]
Q.150 Correct
Q.150 In-correct
Q.150 Unattempt
A beam of light has two wavelengths of 4972Å and 6216Å with a total intensity of 3.6×10−3Wm−2 equally distributed among the two wavelengths. The beam falls normally on an area of 1cm2 of a clean metallic surface of work function 2.3eV. Assume that there is no loss of light by reflection and that each capable photon ejects one electron. The number of photoelectrons liberated in 2 s is approximately:
[Online April 12,2014]
A beam of light has two wavelengths of 4972Å and 6216Å with a total intensity of 3.6×10−3Wm−2 equally distributed among the two wavelengths. The beam falls normally on an area of 1cm2 of a clean metallic surface of work function 2.3eV. Assume that there is no loss of light by reflection and that each capable photon ejects one electron. The number of photoelectrons liberated in 2 s is approximately:
[Online April 12,2014]
Q.151 Correct
Q.151 In-correct
Q.151 Unattempt
A photon of wavelength λ is scattered from an electron, which was at rest. The wavelength shift Δλ is three times of λ and the angle of scattering θ is 60°. The angle at which the electron recoiled is ϕ. The value of tan‌ϕ is : (electron speed is much smaller than the speed of light)
[Online April 11,2014]
A photon of wavelength λ is scattered from an electron, which was at rest. The wavelength shift Δλ is three times of λ and the angle of scattering θ is 60°. The angle at which the electron recoiled is ϕ. The value of tan‌ϕ is : (electron speed is much smaller than the speed of light)
[Online April 11,2014]
Q.152 Correct
Q.152 In-correct
Q.152 Unattempt
Electrons are accelerated through a potential difference V and protons are accelerated through a potential difference 4V. The de-Broglie wavelengths are λe and λp for electrons and protons respectively. The ratio of
λe
λn
 is given by : (given me is mass of electron and mp is mass of proton).
[Online April 23, 2013]
Electrons are accelerated through a potential difference V and protons are accelerated through a potential difference 4V. The de-Broglie wavelengths are λe and λp for electrons and protons respectively. The ratio of
λe
λn
 is given by : (given me is mass of electron and mp is mass of proton).
[Online April 23, 2013]
Q.153 Correct
Q.153 In-correct
Q.153 Unattempt
The anode voltage of a photocell is kept fixed. The wavelength λ of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows :
[2013]
The anode voltage of a photocell is kept fixed. The wavelength λ of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows :
[2013]
Q.154 Correct
Q.154 In-correct
Q.154 Unattempt
In an experiment on photoelectric effect, a student plots stopping potential V0 against reciprocal of the wavelength λ of the incident light for two different metals A and B These are shown in the figure.

Looking at the graphs, you can most appropriately say that:
[Online April 25, 2013]
In an experiment on photoelectric effect, a student plots stopping potential V0 against reciprocal of the wavelength λ of the incident light for two different metals A and B These are shown in the figure.

Looking at the graphs, you can most appropriately say that:
[Online April 25, 2013]
Q.155 Correct
Q.155 In-correct
Q.155 Unattempt
A copper ball of radius 1 cm and work function 4.47eV is irradiated with ultraviolet radiation of wavelength 2500 Å. The effect of irradiation results in the emission of electrons from the ball. Further the ball will acquire charge and due to this there will be a finite value of the potential on the ball. The charge acquired by the ball is :
[Online April 25, 2013]
A copper ball of radius 1 cm and work function 4.47eV is irradiated with ultraviolet radiation of wavelength 2500 Å. The effect of irradiation results in the emission of electrons from the ball. Further the ball will acquire charge and due to this there will be a finite value of the potential on the ball. The charge acquired by the ball is :
[Online April 25, 2013]
Q.156 Correct
Q.156 In-correct
Q.156 Unattempt
This equation has statement 1 and statement 2. Of the four choices given after the statements, choose the one that describes the two statements.
Statement 1: Davisson-Germer experiment established the wave nature of electrons.
Statement 2 : If electrons have wave nature, they can interfere and show diffraction.
[2012]
This equation has statement 1 and statement 2. Of the four choices given after the statements, choose the one that describes the two statements.
Statement 1: Davisson-Germer experiment established the wave nature of electrons.
Statement 2 : If electrons have wave nature, they can interfere and show diffraction.
[2012]
Q.157 Correct
Q.157 In-correct
Q.157 Unattempt
Photoelectrons are ejected from a metal when light of frequency υ falls on it. Pick out the wrong statement from the following.
[Online May 26, 2012]
Photoelectrons are ejected from a metal when light of frequency υ falls on it. Pick out the wrong statement from the following.
[Online May 26, 2012]
Q.158 Correct
Q.158 In-correct
Q.158 Unattempt
This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement 1: A metallic surface is irradiated by a monochromatic light of frequency υ>υ0 (the threshold frequency). If the incident frequency is now doubled, the photocurrent and the maximum kinetic energy are also doubled.
Statement 2: The maximum kinetic energy of photoelectrons emitted from a surface is linearly dependent on the frequency of the incident light. The photocurrent depends only on the intensity of the incident light.
[Online May 19, 2012]
This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements.
Statement 1: A metallic surface is irradiated by a monochromatic light of frequency υ>υ0 (the threshold frequency). If the incident frequency is now doubled, the photocurrent and the maximum kinetic energy are also doubled.
Statement 2: The maximum kinetic energy of photoelectrons emitted from a surface is linearly dependent on the frequency of the incident light. The photocurrent depends only on the intensity of the incident light.
[Online May 19, 2012]
Q.159 Correct
Q.159 In-correct
Q.159 Unattempt
This question has Statement -1 and Statement −2. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement -1 : A metallic surface is irradiated by a monochromatic light of frequency v>v0 (the threshold frequency). The maximum kinetic energy and the stopping potential are Kmax and V0 respectively. If the frequency incident on the surface is doubled, both the Kmax and V0 are also doubled.
Statement -2 : The maximum kinetic energy and the stopping potential of photoelectrons emitted from a surface are linearly dependent on the frequency of incident light.
[2011]
This question has Statement -1 and Statement −2. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement -1 : A metallic surface is irradiated by a monochromatic light of frequency v>v0 (the threshold frequency). The maximum kinetic energy and the stopping potential are Kmax and V0 respectively. If the frequency incident on the surface is doubled, both the Kmax and V0 are also doubled.
Statement -2 : The maximum kinetic energy and the stopping potential of photoelectrons emitted from a surface are linearly dependent on the frequency of incident light.
[2011]
Q.160 Correct
Q.160 In-correct
Q.160 Unattempt
Statement -1 : When ultraviolet light is incident on a photocell, its stopping potential is V0 and the maximum kinetic energy of the photoelectrons is Kmax. When the ultraviolet light is replaced by X -rays, both V0 and Km increase.
Statement -2 : Photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light.
[2010]
Statement -1 : When ultraviolet light is incident on a photocell, its stopping potential is V0 and the maximum kinetic energy of the photoelectrons is Kmax. When the ultraviolet light is replaced by X -rays, both V0 and Km increase.
Statement -2 : Photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light.
[2010]
Q.161 Correct
Q.161 In-correct
Q.161 Unattempt
The surface of a metal is illuminted with the light of 400 nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is :
(hc = 1240 eV.nm)
[2009]
The surface of a metal is illuminted with the light of 400 nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is :
(hc = 1240 eV.nm)
[2009]
Q.162 Correct
Q.162 In-correct
Q.162 Unattempt
Electrons accelerated by potential V are diffracted from a crystal. If d=1Å and i=30°,V should be about (h=6.6×10−34Js,me=9.1×10−31kg, e=1.6×10−19C)
[2008]
Electrons accelerated by potential V are diffracted from a crystal. If d=1Å and i=30°,V should be about (h=6.6×10−34Js,me=9.1×10−31kg, e=1.6×10−19C)
[2008]
Q.163 Correct
Q.163 In-correct
Q.163 Unattempt
If a strong diffraction peak is observed when electrons are incident at an angle i ' from the normal to the crystal planes with distance ' d ' between them (see figure), de Broglie wavelength λdB of electrons can be calculated by the relationship (n is an integer)
[2008]
If a strong diffraction peak is observed when electrons are incident at an angle i ' from the normal to the crystal planes with distance ' d ' between them (see figure), de Broglie wavelength λdB of electrons can be calculated by the relationship (n is an integer)
[2008]
Q.164 Correct
Q.164 In-correct
Q.164 Unattempt
Photon of frequency v has a momentum associated with it. If c is the velocity of light, the momentum is
[2007]
Photon of frequency v has a momentum associated with it. If c is the velocity of light, the momentum is
[2007]
Q.165 Correct
Q.165 In-correct
Q.165 Unattempt
The threshold frequency for a metallic surface corresponds to an energy of 6.2 eV and the stopping potential for a radiation incident on this surface is 5 V. The incident radiation lies in
[2006]
The threshold frequency for a metallic surface corresponds to an energy of 6.2 eV and the stopping potential for a radiation incident on this surface is 5 V. The incident radiation lies in
[2006]
Q.166 Correct
Q.166 In-correct
Q.166 Unattempt
The time taken by a photoelectron to come out after the photon strikes is approximately
[2006]
The time taken by a photoelectron to come out after the photon strikes is approximately
[2006]
Q.167 Correct
Q.167 In-correct
Q.167 Unattempt
The anode voltage of a photocell is kept fixed. The wavelength λ of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows
[2006]
The anode voltage of a photocell is kept fixed. The wavelength λ of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows
[2006]
Q.168 Correct
Q.168 In-correct
Q.168 Unattempt
If the kinetic energy of a free electron doubles, it's de-Broglie wavelength changes by the factor
[2005]
If the kinetic energy of a free electron doubles, it's de-Broglie wavelength changes by the factor
[2005]
Q.169 Correct
Q.169 In-correct
Q.169 Unattempt
A photocell is illuminated by a small bright source placed 1m away. When the same source of light is placed
1
2
m away, the number of electrons emitted by photocathode would
[2005]
A photocell is illuminated by a small bright source placed 1m away. When the same source of light is placed
1
2
m away, the number of electrons emitted by photocathode would
[2005]
Q.170 Correct
Q.170 In-correct
Q.170 Unattempt
A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface is
[2004]
A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface is
[2004]
Q.171 Correct
Q.171 In-correct
Q.171 Unattempt
According to Einstein’s photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal Versus the frequency, of the incident radiation gives a straight line whose slope
[2004]
According to Einstein’s photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal Versus the frequency, of the incident radiation gives a straight line whose slope
[2004]
Q.172 Correct
Q.172 In-correct
Q.172 Unattempt
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
[2004]
The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately
[2004]
Q.173 Correct
Q.173 In-correct
Q.173 Unattempt
Two identical photocathodes receive light of frequencies f1 and f2. If the velocites of the photo electrons (of mass m ) coming out are respectively v1 and v2, then
[2003]
Two identical photocathodes receive light of frequencies f1 and f2. If the velocites of the photo electrons (of mass m ) coming out are respectively v1 and v2, then
[2003]
Q.174 Correct
Q.174 In-correct
Q.174 Unattempt
Formation of covalent bonds in compounds exhibits
[2002]
Formation of covalent bonds in compounds exhibits
[2002]
Q.175 Correct
Q.175 In-correct
Q.175 Unattempt
Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to
[2002]
Sodium and copper have work functions 2.3 eV and 4.5 eV respectively. Then the ratio of the wavelengths is nearest to
[2002]
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