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

A closed organ and an open organ tube are filled by two different gases having same bulk modulus but different densities $\rho_1$ and $\rho_2$, respectively. The frequency of $9^{\text {th }}$ harmonic of closed tube is identical with $4^{\text {th }}$ harmonic of open tube. If the length of the closed tube is 10 cm and the density ratio of the gases is $\rho_1: \rho_2=1: 16$, then the length of the open tube is :



JEE Main 2025 (Online) 22nd January Morning Shift

A closed organ and an open organ tube are filled by two different gases having same bulk modulus but different densities $\rho_1$ and $\rho_2$, respectively. The frequency of $9^{\text {th }}$ harmonic of closed tube is identical with $4^{\text {th }}$ harmonic of open tube. If the length of the closed tube is 10 cm and the density ratio of the gases is $\rho_1: \rho_2=1: 16$, then the length of the open tube is :



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

The equation of a transverse wave travelling along a string is $y(x, t)=4.0 \sin \left[20 \times 10^{-3} x+600 t\right] \mathrm{mm}$, where $x$ is in mm and $t$ is in second. The velocity of the wave is :



JEE Main 2025 (Online) 23rd January Evening Shift

The equation of a transverse wave travelling along a string is $y(x, t)=4.0 \sin \left[20 \times 10^{-3} x+600 t\right] \mathrm{mm}$, where $x$ is in mm and $t$ is in second. The velocity of the wave is :



JEE Main 2025 (Online) 23rd January Evening Shift
Q.3 Correct
Q.3 In-correct
Q.3 Unattempt

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

Assertion A: A sound wave has higher speed in solids than gases.

Reason R: Gases have higher value of Bulk modulus than solids.

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



JEE Main 2025 (Online) 28th January Morning Shift

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

Assertion A: A sound wave has higher speed in solids than gases.

Reason R: Gases have higher value of Bulk modulus than solids.

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



JEE Main 2025 (Online) 28th January Morning Shift
Q.4 Correct
Q.4 In-correct
Q.4 Unattempt
A sinusoidal wave of wavelength 7.5 cm travels a distance of 1.2 cm along the $x$-direction in 0.3 sec . The crest P is at $x=0$ at $\mathrm{t}=0 \mathrm{sec}$ and maximum displacement of the wave is 2 cm . Which equation correctly represents this wave?

JEE Main 2025 (Online) 2nd April Evening Shift
A sinusoidal wave of wavelength 7.5 cm travels a distance of 1.2 cm along the $x$-direction in 0.3 sec . The crest P is at $x=0$ at $\mathrm{t}=0 \mathrm{sec}$ and maximum displacement of the wave is 2 cm . Which equation correctly represents this wave?

JEE Main 2025 (Online) 2nd April Evening Shift
Q.5 Correct
Q.5 In-correct
Q.5 Unattempt

In the resonance experiment, two air columns (closed at one end) of 100 cm and 120 cm long, give 15 beats per second when each one is sounding in the respective fundamental modes. The velocity of sound in the air column is:



JEE Main 2025 (Online) 3rd April Evening Shift

In the resonance experiment, two air columns (closed at one end) of 100 cm and 120 cm long, give 15 beats per second when each one is sounding in the respective fundamental modes. The velocity of sound in the air column is:



JEE Main 2025 (Online) 3rd April Evening Shift
Q.6 Correct
Q.6 In-correct
Q.6 Unattempt

In an experiment with a closed organ pipe, it is filled with water by $\left(\frac{1}{5}\right)$ th of its volume. The frequency of the fundamental note will change by



JEE Main 2025 (Online) 4th April Morning Shift

In an experiment with a closed organ pipe, it is filled with water by $\left(\frac{1}{5}\right)$ th of its volume. The frequency of the fundamental note will change by



JEE Main 2025 (Online) 4th April Morning Shift
Q.7 Correct
Q.7 In-correct
Q.7 Unattempt

Displacement of a wave is expressed as $x(t)=5 \cos \left(628 t+\frac{\pi}{2}\right) \mathrm{m}$. The wavelength of the wave when its velocity is $300 \mathrm{~m} / \mathrm{s}$ is :

$$(\pi=3.14)$$



JEE Main 2025 (Online) 4th April Evening Shift

Displacement of a wave is expressed as $x(t)=5 \cos \left(628 t+\frac{\pi}{2}\right) \mathrm{m}$. The wavelength of the wave when its velocity is $300 \mathrm{~m} / \mathrm{s}$ is :

$$(\pi=3.14)$$



JEE Main 2025 (Online) 4th April Evening Shift
Q.8 Correct
Q.8 In-correct
Q.8 Unattempt

Two harmonic waves moving in the same direction superimpose to form a wave $x=\mathrm{a} \cos (1.5 \mathrm{t}) \cos (50.5 \mathrm{t})$ where t is in seconds. Find the period with which they beat. (close to nearest integer)



JEE Main 2025 (Online) 7th April Morning Shift

Two harmonic waves moving in the same direction superimpose to form a wave $x=\mathrm{a} \cos (1.5 \mathrm{t}) \cos (50.5 \mathrm{t})$ where t is in seconds. Find the period with which they beat. (close to nearest integer)



JEE Main 2025 (Online) 7th April Morning Shift
Q.9 Correct
Q.9 In-correct
Q.9 Unattempt

The equation of a wave travelling on a string is y = sin[20πx + 10πt], where x and t are distance and time in SI units. The minimum distance between two points having the same oscillating speed is :



JEE Main 2025 (Online) 7th April Evening Shift

The equation of a wave travelling on a string is y = sin[20πx + 10πt], where x and t are distance and time in SI units. The minimum distance between two points having the same oscillating speed is :



JEE Main 2025 (Online) 7th April Evening Shift
Q.10 Correct
Q.10 In-correct
Q.10 Unattempt

Two strings with circular cross section and made of same material, are stretched to have same amount of tension. A transverse wave is then made to pass through both the strings. The velocity of the wave in the first string having the radius of cross section R is $v_1$, and that in the other string having radius of cross section R/2 is $v_2$. Then $\frac{v_2}{v_1}$ =



JEE Main 2025 (Online) 8th April Evening Shift

Two strings with circular cross section and made of same material, are stretched to have same amount of tension. A transverse wave is then made to pass through both the strings. The velocity of the wave in the first string having the radius of cross section R is $v_1$, and that in the other string having radius of cross section R/2 is $v_2$. Then $\frac{v_2}{v_1}$ =



JEE Main 2025 (Online) 8th April Evening Shift
Q.11 Correct
Q.11 In-correct
Q.11 Unattempt

The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves, $y_1(x, t) = 4 \sin (kx - \omega t)$ and $y_2(x, t) = 2 \sin (kx - \omega t + \frac{2\pi}{3})$, are:

(Take the angular frequency of initial waves same as $\omega$)



JEE Main 2025 (Online) 8th April Evening Shift

The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves, $y_1(x, t) = 4 \sin (kx - \omega t)$ and $y_2(x, t) = 2 \sin (kx - \omega t + \frac{2\pi}{3})$, are:

(Take the angular frequency of initial waves same as $\omega$)



JEE Main 2025 (Online) 8th April Evening Shift
Q.12 Correct
Q.12 In-correct
Q.12 Unattempt

A closed organ pipe 150cm long gives 7 beats per second with an open organ pipe of length 350cm, both vibrating in fundamental mode. The velocity of sound is _____m∕ s.

[27-Jan-2024 Shift 2]

A closed organ pipe 150cm long gives 7 beats per second with an open organ pipe of length 350cm, both vibrating in fundamental mode. The velocity of sound is _____m∕ s.

[27-Jan-2024 Shift 2]
Q.13 Correct
Q.13 In-correct
Q.13 Unattempt

In a closed organ pipe, the frequency of fundamental note is 30Hz. A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to 110Hz. If the organ pipe has a cross-sectional area of 2cm2, the amount of water poured in the organ tube is _______g. (Take speed of sound in air is 330m∕ s)

[30-Jan-2024 Shift 1]

In a closed organ pipe, the frequency of fundamental note is 30Hz. A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to 110Hz. If the organ pipe has a cross-sectional area of 2cm2, the amount of water poured in the organ tube is _______g. (Take speed of sound in air is 330m∕ s)

[30-Jan-2024 Shift 1]
Q.14 Correct
Q.14 In-correct
Q.14 Unattempt

A point source is emitting sound waves of intensity 16 × 10−8Wm−2 at the origin. The difference in intensity (magnitude only) at two points located at a distances of 2m and 4m from the origin respectively will be______ × 10−8Wm−2.

[30-Jan-2024 Shift 2]

A point source is emitting sound waves of intensity 16 × 10−8Wm−2 at the origin. The difference in intensity (magnitude only) at two points located at a distances of 2m and 4m from the origin respectively will be______ × 10−8Wm−2.

[30-Jan-2024 Shift 2]
Q.15 Correct
Q.15 In-correct
Q.15 Unattempt

The fundamental frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe. If length of the open pipe is 60cm, the length of the closed pipe will be :

[31-Jan-2024 Shift 1]

The fundamental frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe. If length of the open pipe is 60cm, the length of the closed pipe will be :

[31-Jan-2024 Shift 1]
Q.16 Correct
Q.16 In-correct
Q.16 Unattempt

The speed of sound in oxygen at S.T.P. will be approximately:

(Given, R = 8.3JK−1, γ = 1.4)

[31-Jan-2024 Shift 2]

The speed of sound in oxygen at S.T.P. will be approximately:

(Given, R = 8.3JK−1, γ = 1.4)

[31-Jan-2024 Shift 2]
Q.17 Correct
Q.17 In-correct
Q.17 Unattempt

A tuning fork resonates with a sonometer wire of length 1m stretched with a tension of 6N. When the tension in the wire is changed to 54N, the same tuning fork produces 12 beats per second with it. The frequency of the tuning fork is ______Hz.

[1-Feb-2024 Shift 1]

A tuning fork resonates with a sonometer wire of length 1m stretched with a tension of 6N. When the tension in the wire is changed to 54N, the same tuning fork produces 12 beats per second with it. The frequency of the tuning fork is ______Hz.

[1-Feb-2024 Shift 1]
Q.18 Correct
Q.18 In-correct
Q.18 Unattempt
A travelling wave is described by the equation y(x,t)=[0.05sin‌(8x−4t]m
The velocity of the wave is : [all the quantities are in SI unit]
[24-Jan-2023 Shift 1]
A travelling wave is described by the equation y(x,t)=[0.05sin‌(8x−4t]m
The velocity of the wave is : [all the quantities are in SI unit]
[24-Jan-2023 Shift 1]
Q.19 Correct
Q.19 In-correct
Q.19 Unattempt
27. The distance between two consecutive points with phase difference of 60∘ in a wave of frequency 500‌Hz is 6.0m. The velocity with which wave is traveling is ________ km∕ s
[25-Jan-2023 Shift 1]
27. The distance between two consecutive points with phase difference of 60∘ in a wave of frequency 500‌Hz is 6.0m. The velocity with which wave is traveling is ________ km∕ s
[25-Jan-2023 Shift 1]
Q.20 Correct
Q.20 In-correct
Q.20 Unattempt
Match List I with List II

Choose the correct answer from the options given below:
[25-Jan-2023 Shift 2]
Match List I with List II

Choose the correct answer from the options given below:
[25-Jan-2023 Shift 2]
Q.21 Correct
Q.21 In-correct
Q.21 Unattempt
A train blowing a whistle of frequency 320‌Hz approaches an observer standing on the platform at a speed of 66m∕ s. The frequency observed by the observer will be (given speed of sound =330ms−1 ) ________ Hz.
[25-Jan-2023 Shift 2]
A train blowing a whistle of frequency 320‌Hz approaches an observer standing on the platform at a speed of 66m∕ s. The frequency observed by the observer will be (given speed of sound =330ms−1 ) ________ Hz.
[25-Jan-2023 Shift 2]
Q.22 Correct
Q.22 In-correct
Q.22 Unattempt
A person observes two moving trains, 'A' reaching the station and ' B ' leaving the station with equal speed of 30m∕ s. If both trains emit sounds with frequency 300‌Hz, (Speed of sound : 330m∕ s ) approximate difference of frequencies heard by the person will be :
[29-Jan-2023 Shift 1]
A person observes two moving trains, 'A' reaching the station and ' B ' leaving the station with equal speed of 30m∕ s. If both trains emit sounds with frequency 300‌Hz, (Speed of sound : 330m∕ s ) approximate difference of frequencies heard by the person will be :
[29-Jan-2023 Shift 1]
Q.23 Correct
Q.23 In-correct
Q.23 Unattempt
Two simple harmonic waves having equal amplitudes of 8‌cm and equal frequency of 10‌Hz are moving along the same direction. The resultant amplitude is also 8‌cm. The phase difference between the individual waves is degree ________.
[29-Jan-2023 Shift 1]
Two simple harmonic waves having equal amplitudes of 8‌cm and equal frequency of 10‌Hz are moving along the same direction. The resultant amplitude is also 8‌cm. The phase difference between the individual waves is degree ________.
[29-Jan-2023 Shift 1]
Q.24 Correct
Q.24 In-correct
Q.24 Unattempt
The displacement equations of two interfering waves are given by
y1=10sin‌(ωt+‌
π
3
)‌cm,
y2=5[sin‌ωt+√3‌cos‌ω‌t]‌cm‌ respectively. ‌
The amplitude of the resultant wave is ____cm.
[31-Jan-2023 Shift 2]
The displacement equations of two interfering waves are given by
y1=10sin‌(ωt+‌
π
3
)‌cm,
y2=5[sin‌ωt+√3‌cos‌ω‌t]‌cm‌ respectively. ‌
The amplitude of the resultant wave is ____cm.
[31-Jan-2023 Shift 2]
Q.25 Correct
Q.25 In-correct
Q.25 Unattempt
A steel wire with mass per unit length 7.0×10−3‌kg m−1 is under tension of 70N. The speed of transverse waves in the wire will be:
[1-Feb-2023 Shift 1]
A steel wire with mass per unit length 7.0×10−3‌kg m−1 is under tension of 70N. The speed of transverse waves in the wire will be:
[1-Feb-2023 Shift 1]
Q.26 Correct
Q.26 In-correct
Q.26 Unattempt
The ratio of speed of sound in hydrogen gas to the speed of sound in oxygen gas at the same temperature is :
[6-Apr-2023 shift 2]
The ratio of speed of sound in hydrogen gas to the speed of sound in oxygen gas at the same temperature is :
[6-Apr-2023 shift 2]
Q.27 Correct
Q.27 In-correct
Q.27 Unattempt
A person driving car at a constant speed of 15m∕ s is approaching a vertical wall. The person notices a change of 40‌Hz in the frequency of his car's horn upon reflection from the wall. The frequency of horn is Hz.
[6-Apr-2023 shift 1]
A person driving car at a constant speed of 15m∕ s is approaching a vertical wall. The person notices a change of 40‌Hz in the frequency of his car's horn upon reflection from the wall. The frequency of horn is Hz.
[6-Apr-2023 shift 1]
Q.28 Correct
Q.28 In-correct
Q.28 Unattempt
The engine of a train moving with speed 10ms−1 towards a platform sounds a whistle at frequency 400‌Hz. The frequency heard by a passenger inside the train is : (neglect air speed. Speed of sound in air =330ms−1 )
[8-Apr-2023 shift 1]
The engine of a train moving with speed 10ms−1 towards a platform sounds a whistle at frequency 400‌Hz. The frequency heard by a passenger inside the train is : (neglect air speed. Speed of sound in air =330ms−1 )
[8-Apr-2023 shift 1]
Q.29 Correct
Q.29 In-correct
Q.29 Unattempt
An organ pipe 40‌cm long is open at both ends. The speed of sound in air is 360ms−1. The frequency of the second harmonic is ________ Hz.
[8-Apr-2023 shift 1]
An organ pipe 40‌cm long is open at both ends. The speed of sound in air is 360ms−1. The frequency of the second harmonic is ________ Hz.
[8-Apr-2023 shift 1]
Q.30 Correct
Q.30 In-correct
Q.30 Unattempt
A guitar string of length 90‌cm vibrates with a fundamental frequency of 120‌Hz. The length of the string producing a fundamental frequency of 180‌Hz will be ________ cm.
[8-Apr-2023 shift 2]
A guitar string of length 90‌cm vibrates with a fundamental frequency of 120‌Hz. The length of the string producing a fundamental frequency of 180‌Hz will be ________ cm.
[8-Apr-2023 shift 2]
Q.31 Correct
Q.31 In-correct
Q.31 Unattempt
A transverse harmonic wave on a string is given by y(x,t)=5sin‌(6t+0.003x)
where x and y are in cm and t in sec. The wave velocity is _______ ms−1.
[10-Apr-2023 shift 1]
A transverse harmonic wave on a string is given by y(x,t)=5sin‌(6t+0.003x)
where x and y are in cm and t in sec. The wave velocity is _______ ms−1.
[10-Apr-2023 shift 1]
Q.32 Correct
Q.32 In-correct
Q.32 Unattempt
The equation of wave is given by Y=10−2sin‌2π(160t−0.5x+π∕4) where x and Y are in m and t in s. The speed of the wave is ________ km‌h−1.
[11-Apr-2023 shift 1]
The equation of wave is given by Y=10−2sin‌2π(160t−0.5x+π∕4) where x and Y are in m and t in s. The speed of the wave is ________ km‌h−1.
[11-Apr-2023 shift 1]
Q.33 Correct
Q.33 In-correct
Q.33 Unattempt
A car P travelling at 20ms−1 sounds its horn at a frequency of 400‌Hz. Another car Q is travelling behind the first car in the same direction with a velocity 40ms−1. The frequency heard by the passenger of the car Q is approximately [Take, velocity of sound =360ms−1 ]
[11-Apr-2023 shift 2]
A car P travelling at 20ms−1 sounds its horn at a frequency of 400‌Hz. Another car Q is travelling behind the first car in the same direction with a velocity 40ms−1. The frequency heard by the passenger of the car Q is approximately [Take, velocity of sound =360ms−1 ]
[11-Apr-2023 shift 2]
Q.34 Correct
Q.34 In-correct
Q.34 Unattempt
A wire of density 8×103‌kg∕m3 is stretched between two clamps 0.5m apart. The extension developed in the wire is 3.2×10−4m. If Y=8×1010N∕m2, the fundamental frequency of vibration in the wire will be ________ Hz.
[11-Apr-2023 shift 2]
A wire of density 8×103‌kg∕m3 is stretched between two clamps 0.5m apart. The extension developed in the wire is 3.2×10−4m. If Y=8×1010N∕m2, the fundamental frequency of vibration in the wire will be ________ Hz.
[11-Apr-2023 shift 2]
Q.35 Correct
Q.35 In-correct
Q.35 Unattempt
For a certain organ pipe, the first three resonance frequencies are in the ratio of 1:3:5 respectively. If the frequency of fifth harmonic is 405‌Hz and the speed of sound in air is 324ms−1 the length of the organ pipe is ________ m
[12-Apr-2023 shift 1]
For a certain organ pipe, the first three resonance frequencies are in the ratio of 1:3:5 respectively. If the frequency of fifth harmonic is 405‌Hz and the speed of sound in air is 324ms−1 the length of the organ pipe is ________ m
[12-Apr-2023 shift 1]
Q.36 Correct
Q.36 In-correct
Q.36 Unattempt
In an experiment with sonometer when a mass of 180g is attached to the string, it vibrates with fundamental frequency of 30‌Hz. When a mass m is attached, the string vibrates with fundamental frequency of 50‌Hz. The value of m is ________ g.
[13-Apr-2023 shift 2]
In an experiment with sonometer when a mass of 180g is attached to the string, it vibrates with fundamental frequency of 30‌Hz. When a mass m is attached, the string vibrates with fundamental frequency of 50‌Hz. The value of m is ________ g.
[13-Apr-2023 shift 2]
Q.37 Correct
Q.37 In-correct
Q.37 Unattempt
The fundamental frequency of vibration of a string stretched between two rigid support is 50‌Hz. The mass of the string is 18g and its linear mass density is 20g∕m. The speed of the transverse waves so produced in the string is _______ ms−1
[15-Apr-2023 shift 1]
The fundamental frequency of vibration of a string stretched between two rigid support is 50‌Hz. The mass of the string is 18g and its linear mass density is 20g∕m. The speed of the transverse waves so produced in the string is _______ ms−1
[15-Apr-2023 shift 1]
Q.38 Correct
Q.38 In-correct
Q.38 Unattempt
The equations of two waves are given by:
y1=5‌sin‌2‌π(x−vt)‌cm
y2=3‌sin‌2‌π(x−vt+1.5)‌cm
These waves are simultaneously passing through a string. The amplitude of the resulting wave is:
[24-Jun-2022-Shift-1]
The equations of two waves are given by:
y1=5‌sin‌2‌π(x−vt)‌cm
y2=3‌sin‌2‌π(x−vt+1.5)‌cm
These waves are simultaneously passing through a string. The amplitude of the resulting wave is:
[24-Jun-2022-Shift-1]
Q.39 Correct
Q.39 In-correct
Q.39 Unattempt
Two light beams of intensities in the ratio of 9:4 are allowed to interfere. The ratio of the intensity of maxima and minima will be :
[24-Jun-2022-Shift-2]
Two light beams of intensities in the ratio of 9:4 are allowed to interfere. The ratio of the intensity of maxima and minima will be :
[24-Jun-2022-Shift-2]
Q.40 Correct
Q.40 In-correct
Q.40 Unattempt
Two travelling waves of equal amplitudes and equal frequencies move in opposite directions along a string. They interfere to produce a stationary wave whose equation is given by y=(10‌cos‌π‌x‌sin‌
2πt
T
)‌cm
The amplitude of the particle at x=‌
4
3
‌cm will be _____cm.
[24-Jun-2022-Shift-2]
Two travelling waves of equal amplitudes and equal frequencies move in opposite directions along a string. They interfere to produce a stationary wave whose equation is given by y=(10‌cos‌π‌x‌sin‌
2πt
T
)‌cm
The amplitude of the particle at x=‌
4
3
‌cm will be _____cm.
[24-Jun-2022-Shift-2]
Q.41 Correct
Q.41 In-correct
Q.41 Unattempt
The first overtone frequency of an open organ pipe is equal to the fundamental frequency of a closed organ pipe. If the length of the closed organ pipe is 20‌cm. The length of the open organ pipe is ______cm.
[25-Jun-2022-Shift-1]
The first overtone frequency of an open organ pipe is equal to the fundamental frequency of a closed organ pipe. If the length of the closed organ pipe is 20‌cm. The length of the open organ pipe is ______cm.
[25-Jun-2022-Shift-1]
Q.42 Correct
Q.42 In-correct
Q.42 Unattempt
A set of 20 tuning forks is arranged in a series of increasing frequencies. If each fork gives 4 beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first, then the frequency of last fork is _____ Hz
[26-Jun-2022-Shift-2]
A set of 20 tuning forks is arranged in a series of increasing frequencies. If each fork gives 4 beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first, then the frequency of last fork is _____ Hz
[26-Jun-2022-Shift-2]
Q.43 Correct
Q.43 In-correct
Q.43 Unattempt
An observer moves towards a stationary source of sound with a velocity equal to one-fifth of the velocity of sound. The percentage change in the frequency will be:
[27-Jun-2022-Shift-1]
An observer moves towards a stationary source of sound with a velocity equal to one-fifth of the velocity of sound. The percentage change in the frequency will be:
[27-Jun-2022-Shift-1]
Q.44 Correct
Q.44 In-correct
Q.44 Unattempt
If a wave gets refracted into a denser medium, then which of the following is true?
[27-Jun-2022-Shift-2]
If a wave gets refracted into a denser medium, then which of the following is true?
[27-Jun-2022-Shift-2]
Q.45 Correct
Q.45 In-correct
Q.45 Unattempt
A radar sends an electromagnetic signal of electric field (E0)=2.25V∕m and magnetic field (B0)=1.5×10−8T which strikes a target on line of sight at a distance of 3‌km in a medium. After that, a part of signal (echo) reflects back towards the radar with same velocity and by same path. If the signal was transmitted at time t=0 from radar, then after how much time echo will reach to the radar?
[28-Jun-2022-Shift-1]
A radar sends an electromagnetic signal of electric field (E0)=2.25V∕m and magnetic field (B0)=1.5×10−8T which strikes a target on line of sight at a distance of 3‌km in a medium. After that, a part of signal (echo) reflects back towards the radar with same velocity and by same path. If the signal was transmitted at time t=0 from radar, then after how much time echo will reach to the radar?
[28-Jun-2022-Shift-1]
Q.46 Correct
Q.46 In-correct
Q.46 Unattempt
The velocity of sound in a gas, in which two wavelengths 4.08m and 4.16m produce 40 beats in 12s, will be :
[28-Jun-2022-Shift-1]
The velocity of sound in a gas, in which two wavelengths 4.08m and 4.16m produce 40 beats in 12s, will be :
[28-Jun-2022-Shift-1]
Q.47 Correct
Q.47 In-correct
Q.47 Unattempt
A tunning fork of frequency 340‌Hz resonates in the fundamental mode with an air column of length 125‌cm in a cylindrical tube closed at one end. When water is slowly poured in it, the minimum height of water required for observing resonance once again is _____cm.
(Velocity of sound in air is 340ms−1 )
[28-Jun-2022-Shift-2]
A tunning fork of frequency 340‌Hz resonates in the fundamental mode with an air column of length 125‌cm in a cylindrical tube closed at one end. When water is slowly poured in it, the minimum height of water required for observing resonance once again is _____cm.
(Velocity of sound in air is 340ms−1 )
[28-Jun-2022-Shift-2]
Q.48 Correct
Q.48 In-correct
Q.48 Unattempt
A longitudinal wave is represented by x=10‌sin‌2‌π(nt−‌
x
λ
)‌cm. The maximum particle velocity will be four times the wave velocity if the determined value of wavelength is equal to:
[29-Jun-2022-Shift-1]
A longitudinal wave is represented by x=10‌sin‌2‌π(nt−‌
x
λ
)‌cm. The maximum particle velocity will be four times the wave velocity if the determined value of wavelength is equal to:
[29-Jun-2022-Shift-1]
Q.49 Correct
Q.49 In-correct
Q.49 Unattempt
In an experiment to determine the velocity of sound in air at room temperature using a resonance tube, the first resonance is observed when the air column has a length of 20.0‌cm for a tuning fork of frequency 400‌Hz is used. The velocity of the sound at room temperature is 336ms−1. The third resonance is observed when the air column has a length of ___cm.
[29-Jun-2022-Shift-2]
In an experiment to determine the velocity of sound in air at room temperature using a resonance tube, the first resonance is observed when the air column has a length of 20.0‌cm for a tuning fork of frequency 400‌Hz is used. The velocity of the sound at room temperature is 336ms−1. The third resonance is observed when the air column has a length of ___cm.
[29-Jun-2022-Shift-2]
Q.50 Correct
Q.50 In-correct
Q.50 Unattempt
An observer is riding on a bicycle and moving towards a hill at 18kmh−1. He hears a sound from a source at some distance behind him directly as well as after its reflection from the hill. If the original frequency of the sound as emitted by source is 640Hz and velocity of the sound in air is 320m∕s, the beat frequency between the two sounds heard by observer will be Hz.
[25-Jul-2022-Shift-1]
An observer is riding on a bicycle and moving towards a hill at 18kmh−1. He hears a sound from a source at some distance behind him directly as well as after its reflection from the hill. If the original frequency of the sound as emitted by source is 640Hz and velocity of the sound in air is 320m∕s, the beat frequency between the two sounds heard by observer will be Hz.
[25-Jul-2022-Shift-1]
Q.51 Correct
Q.51 In-correct
Q.51 Unattempt
When a car is approaching the observer, the frequency of horn is 100‌Hz. After passing the observer, it is 50‌Hz. If the observer moves with the car, the frequency will be ‌
x
3
‌Hz where x= __________.
[26-Jul-2022-Shift-1]
When a car is approaching the observer, the frequency of horn is 100‌Hz. After passing the observer, it is 50‌Hz. If the observer moves with the car, the frequency will be ‌
x
3
‌Hz where x= __________.
[26-Jul-2022-Shift-1]
Q.52 Correct
Q.52 In-correct
Q.52 Unattempt
A transverse wave is represented by y=2‌sin(ωt−kx)‌cm. The value of wavelength (in cm ) for which the wave velocity becomes equal to the maximum particle velocity, will be :
[26-Jul-2022-Shift-2]
A transverse wave is represented by y=2‌sin(ωt−kx)‌cm. The value of wavelength (in cm ) for which the wave velocity becomes equal to the maximum particle velocity, will be :
[26-Jul-2022-Shift-2]
Q.53 Correct
Q.53 In-correct
Q.53 Unattempt
A wire of length 30‌cm, stretched between rigid supports, has it's n‌th ‌ and (n+1)‌th ‌ harmonics at 400 Hz and 450‌Hz, respectively. If tension in the string is 2700N, it's linear mass density is _________ kg∕m.
[27-Jul-2022-Shift-2]
A wire of length 30‌cm, stretched between rigid supports, has it's n‌th ‌ and (n+1)‌th ‌ harmonics at 400 Hz and 450‌Hz, respectively. If tension in the string is 2700N, it's linear mass density is _________ kg∕m.
[27-Jul-2022-Shift-2]
Q.54 Correct
Q.54 In-correct
Q.54 Unattempt
In the wave equation y−0.5‌sin‌
2π
λ
(400t−x)m the velocity of the wave will be:
[28-Jul-2022-Shift-1]
In the wave equation y−0.5‌sin‌
2π
λ
(400t−x)m the velocity of the wave will be:
[28-Jul-2022-Shift-1]
Q.55 Correct
Q.55 In-correct
Q.55 Unattempt
The frequency of echo will be _______ Hz if the train blowing a whistle of frequency 320‌Hz is moving with a velocity of 36‌km∕h towards a hill from which an echo is heard by the train driver. Velocity of sound in air is 330m∕s.
[28-Jul-2022-Shift-1]
The frequency of echo will be _______ Hz if the train blowing a whistle of frequency 320‌Hz is moving with a velocity of 36‌km∕h towards a hill from which an echo is heard by the train driver. Velocity of sound in air is 330m∕s.
[28-Jul-2022-Shift-1]
Q.56 Correct
Q.56 In-correct
Q.56 Unattempt
Two light beams of intensities 4I and 9I interfere on a screen. The phase difference between these beams on the screen at point A is zero and at point B is π. The difference of resultant intensities, at the point A and B, will be ________ I.
[29-Jul-2022-Shift-1]
Two light beams of intensities 4I and 9I interfere on a screen. The phase difference between these beams on the screen at point A is zero and at point B is π. The difference of resultant intensities, at the point A and B, will be ________ I.
[29-Jul-2022-Shift-1]
Q.57 Correct
Q.57 In-correct
Q.57 Unattempt
The speed of a transverse wave passing through a string of length 50‌cm and mass 10g is 60ms−1. The area of cross-section of the wire is 2.0mm2 and its Young's modulus is 1.2×1011Nm−2. The extension of the wire over its natural length due to its tension will be x×10−5m. The value of x is _______.
[29-Jul-2022-Shift-2]
The speed of a transverse wave passing through a string of length 50‌cm and mass 10g is 60ms−1. The area of cross-section of the wire is 2.0mm2 and its Young's modulus is 1.2×1011Nm−2. The extension of the wire over its natural length due to its tension will be x×10−5m. The value of x is _______.
[29-Jul-2022-Shift-2]
Q.58 Correct
Q.58 In-correct
Q.58 Unattempt
The mass per unit length of a uniform wire is 0.135g∕cm. A transverse wave of the form y=−0.21‌sin(x+30t) is produced in it, where x is in metre and t is in second. Then, the expected value of tension in the wire is x×10−2N. Value of x is ......... (Round-off to the nearest integer)
[26 Feb 2021 Shift 1]
The mass per unit length of a uniform wire is 0.135g∕cm. A transverse wave of the form y=−0.21‌sin(x+30t) is produced in it, where x is in metre and t is in second. Then, the expected value of tension in the wire is x×10−2N. Value of x is ......... (Round-off to the nearest integer)
[26 Feb 2021 Shift 1]
Q.59 Correct
Q.59 In-correct
Q.59 Unattempt
Which of the following equations represents a travelling wave?
[24 Feb 2021 Shift 2]
Which of the following equations represents a travelling wave?
[24 Feb 2021 Shift 2]
Q.60 Correct
Q.60 In-correct
Q.60 Unattempt
A tuning fork A of unknown frequency produces 5 beats/s with a fork of known frequency 340Hz. When fork A is filled, the beat frequency decreases to 2 beats\/s. What is the frequency of fork A ?
[26 Feb 2021 Shift 2]
A tuning fork A of unknown frequency produces 5 beats/s with a fork of known frequency 340Hz. When fork A is filled, the beat frequency decreases to 2 beats\/s. What is the frequency of fork A ?
[26 Feb 2021 Shift 2]
Q.61 Correct
Q.61 In-correct
Q.61 Unattempt
Two cars are approaching each other at an equal speed of 7.2km∕h. When they see each other, both blow horns having frequency of 676Hz. The beat frequency heard by each driver will be ........ Hz.
[Velocity of sound in air is 340m∕s.]
[24 Feb 2021 Shift 2]
Two cars are approaching each other at an equal speed of 7.2km∕h. When they see each other, both blow horns having frequency of 676Hz. The beat frequency heard by each driver will be ........ Hz.
[Velocity of sound in air is 340m∕s.]
[24 Feb 2021 Shift 2]
Q.62 Correct
Q.62 In-correct
Q.62 Unattempt
A sound wave of frequency 245Hz travels with the speed of 300ms−1 along the positive X-axis. Each point of the wave moves to and from through a total distance of 6cm. What will be the mathematical expression of this travelling wave?
[17 Mar 2021 Shift 2]
A sound wave of frequency 245Hz travels with the speed of 300ms−1 along the positive X-axis. Each point of the wave moves to and from through a total distance of 6cm. What will be the mathematical expression of this travelling wave?
[17 Mar 2021 Shift 2]
Q.63 Correct
Q.63 In-correct
Q.63 Unattempt
A closed organ pipe of length L and an open organ pipe contain gases of densities ρ1 and ρ2 respectively. The compressibility of gases are equal in both the pipes. Both the pipes are vibrating in their first overtone with same frequency. The length of the open pipe is ‌
x
3
L√‌
ρ1
ρ2
 where x is ......
(Round off to the nearest integer)
[16 Mar 2021 Shift 2]
A closed organ pipe of length L and an open organ pipe contain gases of densities ρ1 and ρ2 respectively. The compressibility of gases are equal in both the pipes. Both the pipes are vibrating in their first overtone with same frequency. The length of the open pipe is ‌
x
3
L√‌
ρ1
ρ2
 where x is ......
(Round off to the nearest integer)
[16 Mar 2021 Shift 2]
Q.64 Correct
Q.64 In-correct
Q.64 Unattempt
The difference in the number of waves when yellow light propagates through air and vacuum columns of the same thickness is one. The thickness of the air column is ______ mm.
[Refractive index of air = 1.0003, wavelength of yellow light in vacuum = 6000 Å]
[27 Jul 2021 Shift 2]
The difference in the number of waves when yellow light propagates through air and vacuum columns of the same thickness is one. The thickness of the air column is ______ mm.
[Refractive index of air = 1.0003, wavelength of yellow light in vacuum = 6000 Å]
[27 Jul 2021 Shift 2]
Q.65 Correct
Q.65 In-correct
Q.65 Unattempt
The amplitude of wave disturbance propagating in the positive x-direction is given by y=
1
(1+x)2
 at time t=0 and y=
1
1+(x−2)2
 at t=1s, where x and y are in meres. The shape of wave does not change during the propagation. The velocity of the wave will be ____m∕s.
[20 Jul 2021 Shift 1]
The amplitude of wave disturbance propagating in the positive x-direction is given by y=
1
(1+x)2
 at time t=0 and y=
1
1+(x−2)2
 at t=1s, where x and y are in meres. The shape of wave does not change during the propagation. The velocity of the wave will be ____m∕s.
[20 Jul 2021 Shift 1]
Q.66 Correct
Q.66 In-correct
Q.66 Unattempt
The frequency of a car horn encountered a change from 400 Hz to 500 Hz. When the car approaches a vertical wall. If the speed of sound is 330 m/s.
Then the speed of car is ______ km/h.

[20 Jul 2021 Shift 1]
The frequency of a car horn encountered a change from 400 Hz to 500 Hz. When the car approaches a vertical wall. If the speed of sound is 330 m/s.
Then the speed of car is ______ km/h.

[20 Jul 2021 Shift 1]
Q.67 Correct
Q.67 In-correct
Q.67 Unattempt
A one metre long (both ends open) organ pipe is kept in a gas that has double the density of air at STP. Assuming the speed of sound in air at STP is 300 m/s, the frequency difference between the fundamental and second harmonic of this pipe is ______ Hz.
[NA 8 Jan. 2020 (I)]
A one metre long (both ends open) organ pipe is kept in a gas that has double the density of air at STP. Assuming the speed of sound in air at STP is 300 m/s, the frequency difference between the fundamental and second harmonic of this pipe is ______ Hz.
[NA 8 Jan. 2020 (I)]
Q.68 Correct
Q.68 In-correct
Q.68 Unattempt
A transverse wave travels on a taut steel wire with a velocity of v when tension in it is 2.06×104N. When the tension is changed to T, the velocity changed to
v
2
. The value of T is close to:
[8 Jan. 2020 (II)]
A transverse wave travels on a taut steel wire with a velocity of v when tension in it is 2.06×104N. When the tension is changed to T, the velocity changed to
v
2
. The value of T is close to:
[8 Jan. 2020 (II)]
Q.69 Correct
Q.69 In-correct
Q.69 Unattempt
Speed of a transverse wave on a straight wire (mass 6.0 g, length 60cm and area of cross-section 1.0mm2 ) is 90 ms−1. If the Young's modulus of wire is 16×1011Nm−2 the extension of wire over its natural length is:
[7 Jan. 2020 (I)]
Speed of a transverse wave on a straight wire (mass 6.0 g, length 60cm and area of cross-section 1.0mm2 ) is 90 ms−1. If the Young's modulus of wire is 16×1011Nm−2 the extension of wire over its natural length is:
[7 Jan. 2020 (I)]
Q.70 Correct
Q.70 In-correct
Q.70 Unattempt
A wire of length L and mass per unit length 6.0×10–3kgm–1 is put under tension of 540 N. Two consecutive frequencies that it resonates at are: 420 Hz and 490 Hz.
Then L in meters is:
[9 Jan. 2020 (II)]
A wire of length L and mass per unit length 6.0×10–3kgm–1 is put under tension of 540 N. Two consecutive frequencies that it resonates at are: 420 Hz and 490 Hz.
Then L in meters is:
[9 Jan. 2020 (II)]
Q.71 Correct
Q.71 In-correct
Q.71 Unattempt
There harmonic waves having equal frequency v and same intensity I0, have phase angles 0,
π
4
 and −
π
4
 respectively. When they are superimposed the intensity of the resultant wave is close to:
[9 Jan. 2020 I]
There harmonic waves having equal frequency v and same intensity I0, have phase angles 0,
π
4
 and −
π
4
 respectively. When they are superimposed the intensity of the resultant wave is close to:
[9 Jan. 2020 I]
Q.72 Correct
Q.72 In-correct
Q.72 Unattempt
A stationary observer receives sound from two identical tuning forks, one of which approaches and the other one recedes with the same speed (much less than the speed of sound). The observer hears 2 beats/sec. The oscillation frequency of each tuning fork is v0=1400 Hz and the velocity of sound in air is 350 m/s. The speed of each tuning fork is close to:
[7 Jan. 2020 I]
A stationary observer receives sound from two identical tuning forks, one of which approaches and the other one recedes with the same speed (much less than the speed of sound). The observer hears 2 beats/sec. The oscillation frequency of each tuning fork is v0=1400 Hz and the velocity of sound in air is 350 m/s. The speed of each tuning fork is close to:
[7 Jan. 2020 I]
Q.73 Correct
Q.73 In-correct
Q.73 Unattempt
Assume that the displacement (s) of air is proportional to the pressure difference (Δp) created by a sound wave. Displacement (s) further depends on the speed of sound(v), density of air ( ρ ) and the frequency ( f ). If Δp∼ 10Pa, v∼300m∕s,ρ∼1kg∕m3 and f∼1000Hz, then swill be of the order of (take the multiplicative constant to be 1 )
[Sep. 05, 2020 (I)]
Assume that the displacement (s) of air is proportional to the pressure difference (Δp) created by a sound wave. Displacement (s) further depends on the speed of sound(v), density of air ( ρ ) and the frequency ( f ). If Δp∼ 10Pa, v∼300m∕s,ρ∼1kg∕m3 and f∼1000Hz, then swill be of the order of (take the multiplicative constant to be 1 )
[Sep. 05, 2020 (I)]
Q.74 Correct
Q.74 In-correct
Q.74 Unattempt
For a transverse wave travelling along a straight line, the distance between two peaks (crests) is 5m, while the distance between one crest and one trough is 1.5m. The possible wavelengths (in m ) of the waves are :
[Sep. 04, 2020 (I)]
For a transverse wave travelling along a straight line, the distance between two peaks (crests) is 5m, while the distance between one crest and one trough is 1.5m. The possible wavelengths (in m ) of the waves are :
[Sep. 04, 2020 (I)]
Q.75 Correct
Q.75 In-correct
Q.75 Unattempt
In a resonance tube experiment when the tube is filled with water up to a height of 17.0 cm from bottom, it resonates with a given tuning fork. When the water level is raised the next resonance with the same tuning fork occurs at a height of 24.5 cm. If the velocity of sound in air is 330 m/s, the tuning fork frequency is :
[Sep. 05, 2020 (I)]
In a resonance tube experiment when the tube is filled with water up to a height of 17.0 cm from bottom, it resonates with a given tuning fork. When the water level is raised the next resonance with the same tuning fork occurs at a height of 24.5 cm. If the velocity of sound in air is 330 m/s, the tuning fork frequency is :
[Sep. 05, 2020 (I)]
Q.76 Correct
Q.76 In-correct
Q.76 Unattempt
A uniform thin rope of length 12 m and mass 6 kg hangs vertically from a rigid support and a block of mass 2 kg is attached to its free end. A transverse short wave-train of wavelength 6 cm is produced at the lower end of the rope. What is the wavelength of the wave train (in cm) when it reaches the top of the rope ?
[Sep. 03, 2020 (I)]
A uniform thin rope of length 12 m and mass 6 kg hangs vertically from a rigid support and a block of mass 2 kg is attached to its free end. A transverse short wave-train of wavelength 6 cm is produced at the lower end of the rope. What is the wavelength of the wave train (in cm) when it reaches the top of the rope ?
[Sep. 03, 2020 (I)]
Q.77 Correct
Q.77 In-correct
Q.77 Unattempt
Two identical strings X and Z made of same material have tension TX and TZ in them. If their fundamental frequencies are 450Hz and 300Hz, respectively, then the ratio TX∕TZ is:
[Sep. 02, 2020 (I)]
Two identical strings X and Z made of same material have tension TX and TZ in them. If their fundamental frequencies are 450Hz and 300Hz, respectively, then the ratio TX∕TZ is:
[Sep. 02, 2020 (I)]
Q.78 Correct
Q.78 In-correct
Q.78 Unattempt
A wire of density 9×10−3kgcm−3 is stretched between two clamps 1m apart. The resulting strain in the wire is 4.9×10−4. The lowest frequency of the transverse vibrations in the wire is (Young's modulus of wire Y=9×1010Nm−2 ), (to the nearest integer),___________.
[Sep. 02,2020 (II)]
A wire of density 9×10−3kgcm−3 is stretched between two clamps 1m apart. The resulting strain in the wire is 4.9×10−4. The lowest frequency of the transverse vibrations in the wire is (Young's modulus of wire Y=9×1010Nm−2 ), (to the nearest integer),___________.
[Sep. 02,2020 (II)]
Q.79 Correct
Q.79 In-correct
Q.79 Unattempt
A sound source S is moving along a straight track with speed v, and is emitting sound of frequency v0 (see figure). An observer is standing at a finite distance, at the point O, from the track. The time variation of frequency heard by the observer is best represented by: (t0 represents the instant when the distance between the source and observer is minimum)
[Sep. 06, 2020 (I)]
A sound source S is moving along a straight track with speed v, and is emitting sound of frequency v0 (see figure). An observer is standing at a finite distance, at the point O, from the track. The time variation of frequency heard by the observer is best represented by: (t0 represents the instant when the distance between the source and observer is minimum)
[Sep. 06, 2020 (I)]
Q.80 Correct
Q.80 In-correct
Q.80 Unattempt
A driver in a car, approaching a vertical wall notices that the frequency of his car horn, has changed from 440 Hz to 480 Hz, when it gets reflected from the wall. If the speed of sound in air is 345 m/s, then the speed of the car is :
[Sep. 05, 2020 (II)]
A driver in a car, approaching a vertical wall notices that the frequency of his car horn, has changed from 440 Hz to 480 Hz, when it gets reflected from the wall. If the speed of sound in air is 345 m/s, then the speed of the car is :
[Sep. 05, 2020 (II)]
Q.81 Correct
Q.81 In-correct
Q.81 Unattempt
The driver of a bus approaching a big wall notices that the frequency of his bus’s horn changes from 420 Hz to 490 Hz when he hears it after it gets reflected from the wall. Find the speed of the bus if speed of the sound is 330 ms‌–1.
[Sep. 04, 2020 (II)]
The driver of a bus approaching a big wall notices that the frequency of his bus’s horn changes from 420 Hz to 490 Hz when he hears it after it gets reflected from the wall. Find the speed of the bus if speed of the sound is 330 ms‌–1.
[Sep. 04, 2020 (II)]
Q.82 Correct
Q.82 In-correct
Q.82 Unattempt
Magnetic materials used for making permanent magnets (P) and magnets in a transformer (T) have different properties of the following, which property best matches for the type of magnet required?
[Sep. 02, 2020 (I)]
Magnetic materials used for making permanent magnets (P) and magnets in a transformer (T) have different properties of the following, which property best matches for the type of magnet required?
[Sep. 02, 2020 (I)]
Q.83 Correct
Q.83 In-correct
Q.83 Unattempt
A travelling harmonic wave is represented by the equation y(x,t)=10−3‌sin(50t+2x), where x and y are in meter and t is in seconds. Which of the following is a correct statement about the wave?
[12 Jan. 2019 I]
A travelling harmonic wave is represented by the equation y(x,t)=10−3‌sin(50t+2x), where x and y are in meter and t is in seconds. Which of the following is a correct statement about the wave?
[12 Jan. 2019 I]
Q.84 Correct
Q.84 In-correct
Q.84 Unattempt
Equation of travelling wave on a stretched string of linear density 5 g/m is y=0.03‌sin(450t−9x) where distance and time are measured in SI units. The tension in the string is:
[11 Jan 2019 (I)]
Equation of travelling wave on a stretched string of linear density 5 g/m is y=0.03‌sin(450t−9x) where distance and time are measured in SI units. The tension in the string is:
[11 Jan 2019 (I)]
Q.85 Correct
Q.85 In-correct
Q.85 Unattempt
A heavy ball of mass M is suspended from the ceiling of a car by a light string of mass m (m < < M). When the car is at rest, the speeed of transverse waves in the string is 60 ms‌–1. when the car has acceleration a, the wave-speed increases to 60.5 ms‌–1. The value of a, in terms of gravitational acceleration g, is closest to:
[9 Jan. 2019 (I)]
A heavy ball of mass M is suspended from the ceiling of a car by a light string of mass m (m < < M). When the car is at rest, the speeed of transverse waves in the string is 60 ms‌–1. when the car has acceleration a, the wave-speed increases to 60.5 ms‌–1. The value of a, in terms of gravitational acceleration g, is closest to:
[9 Jan. 2019 (I)]
Q.86 Correct
Q.86 In-correct
Q.86 Unattempt
A closed organ pipe has a fundamental frequency of 1.5 kHz. The number of overtones that can be distinctly heard by a person with this organ pipe will be: (Assume that the highest frequency a person can hear is 20,000 Hz)
[10 Jan. 2019 (I)]
A closed organ pipe has a fundamental frequency of 1.5 kHz. The number of overtones that can be distinctly heard by a person with this organ pipe will be: (Assume that the highest frequency a person can hear is 20,000 Hz)
[10 Jan. 2019 (I)]
Q.87 Correct
Q.87 In-correct
Q.87 Unattempt
A string of length 1 m and mass 5 g is fixed at both ends. The tension in the string is 8.0 N. The string is set into vibration using an external vibrator of frequency 100 Hz. The separation between successive nodes on the string is close to:
[10 Jan. 2019 (I)]
A string of length 1 m and mass 5 g is fixed at both ends. The tension in the string is 8.0 N. The string is set into vibration using an external vibrator of frequency 100 Hz. The separation between successive nodes on the string is close to:
[10 Jan. 2019 (I)]
Q.88 Correct
Q.88 In-correct
Q.88 Unattempt
A resonance tube is old and has jagged end. It is still used in the laboratory to determine velocity of sound in air. A tuning fork of frequency 512 Hz produces first resonance when the tube is filled with water to a mark 11 cm below a reference mark, near the open end of the tube. The experiment is repeated with another fork of frequency 256 Hz which produces first resonance when water reaches a mark 27 cm below the reference mark. The velocity of sound in air, obtained in the experiment, is close to:
[12 Jan. 2019 II]
A resonance tube is old and has jagged end. It is still used in the laboratory to determine velocity of sound in air. A tuning fork of frequency 512 Hz produces first resonance when the tube is filled with water to a mark 11 cm below a reference mark, near the open end of the tube. The experiment is repeated with another fork of frequency 256 Hz which produces first resonance when water reaches a mark 27 cm below the reference mark. The velocity of sound in air, obtained in the experiment, is close to:
[12 Jan. 2019 II]
Q.89 Correct
Q.89 In-correct
Q.89 Unattempt
A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observer is f1 If the speed of the train is reduced to 17 m/s, the frequency registered is f2 If speed of sound is 340 m/s, then the ratio f1∕f2 is:
[10 Jan. 2019 I]
A train moves towards a stationary observer with speed 34 m/s. The train sounds a whistle and its frequency registered by the observer is f1 If the speed of the train is reduced to 17 m/s, the frequency registered is f2 If speed of sound is 340 m/s, then the ratio f1∕f2 is:
[10 Jan. 2019 I]
Q.90 Correct
Q.90 In-correct
Q.90 Unattempt
A musician using an open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to:
[9 Jan. 2019 II]
A musician using an open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to:
[9 Jan. 2019 II]
Q.91 Correct
Q.91 In-correct
Q.91 Unattempt
A progressive wave travelling along the positive x -direction is represented by y(x,t)=A‌sin(kx−ωt+ϕ). Its snapshot at t=0 is given in the figure.

For this wave, the phase ϕ is:
[12 April 2019 I]
A progressive wave travelling along the positive x -direction is represented by y(x,t)=A‌sin(kx−ωt+ϕ). Its snapshot at t=0 is given in the figure.

For this wave, the phase ϕ is:
[12 April 2019 I]
Q.92 Correct
Q.92 In-correct
Q.92 Unattempt
A small speaker delivers 2W of audio output. At what distance from the speaker will one detect 120dB intensity sound ? [Given reference intensity of sound as 10−12W∕m2]
[12 April 2019 II]
A small speaker delivers 2W of audio output. At what distance from the speaker will one detect 120dB intensity sound ? [Given reference intensity of sound as 10−12W∕m2]
[12 April 2019 II]
Q.93 Correct
Q.93 In-correct
Q.93 Unattempt
The pressure wave, P=0.01‌sin[1000t−3x]‌Nm−2, corresponds to the sound produced by a vibrating blade on a day when atmospheric temperature is 0°C. On some other day when temperature is T, the speed of sound produced by the same blade and at the same frequency is found to be 336ms−1. Approximate value of T is:
[9 April 2019 I]
The pressure wave, P=0.01‌sin[1000t−3x]‌Nm−2, corresponds to the sound produced by a vibrating blade on a day when atmospheric temperature is 0°C. On some other day when temperature is T, the speed of sound produced by the same blade and at the same frequency is found to be 336ms−1. Approximate value of T is:
[9 April 2019 I]
Q.94 Correct
Q.94 In-correct
Q.94 Unattempt
A tuning fork of frequency 480 Hz is used in an experiment for measuring speed of sound (v) in air by resonance tube method. Resonance is observed to occur at two successive lengths of the air column, l1=30cm and l2=70cm . Then, v is equal to :
[12 April 2019 (II)]
A tuning fork of frequency 480 Hz is used in an experiment for measuring speed of sound (v) in air by resonance tube method. Resonance is observed to occur at two successive lengths of the air column, l1=30cm and l2=70cm . Then, v is equal to :
[12 April 2019 (II)]
Q.95 Correct
Q.95 In-correct
Q.95 Unattempt
A string 2.0 m long and fixed at its ends is driven by a 240 Hz vibrator. The string vibrates in its third harmonic mode.
The speed of the wave and its fundamental frequency is:
[9 April 2019 (II)]
A string 2.0 m long and fixed at its ends is driven by a 240 Hz vibrator. The string vibrates in its third harmonic mode.
The speed of the wave and its fundamental frequency is:
[9 April 2019 (II)]
Q.96 Correct
Q.96 In-correct
Q.96 Unattempt
A string is clamped at both the ends and it is vibrating in its 4th harmonic. The equation of the stationary wave is Y =0.3‌sin(0.157x)‌cos(200At). The length of the string is:
(All quantities are in SI units.)
[9 April 2019 (I)]
A string is clamped at both the ends and it is vibrating in its 4th harmonic. The equation of the stationary wave is Y =0.3‌sin(0.157x)‌cos(200At). The length of the string is:
(All quantities are in SI units.)
[9 April 2019 (I)]
Q.97 Correct
Q.97 In-correct
Q.97 Unattempt
A wire of length 2L, is made by joining two wires A and B of same length but different radii r and 2r and made of the same material. It is vibrating at a frequency such that the joint of the two wires forms a node. If the number of antinodes in wire A is p and that in B is q then the ratio p : q is :

[8 April 2019 (I)]
A wire of length 2L, is made by joining two wires A and B of same length but different radii r and 2r and made of the same material. It is vibrating at a frequency such that the joint of the two wires forms a node. If the number of antinodes in wire A is p and that in B is q then the ratio p : q is :

[8 April 2019 (I)]
Q.98 Correct
Q.98 In-correct
Q.98 Unattempt
The correct figure that shows, schematically, the wave pattern produced by superposition of two waves of frequencies 9 Hz and 11 Hz is :
[10 April 2019 II]
The correct figure that shows, schematically, the wave pattern produced by superposition of two waves of frequencies 9 Hz and 11 Hz is :
[10 April 2019 II]
Q.99 Correct
Q.99 In-correct
Q.99 Unattempt
A submarine (A) travelling at 18 km/hr is being chased along the line of its velocity by another submarine (B) travelling at 27 km/hr. B sends a sonar signal of 500 Hz to detect A and receives a reflected sound of frequency v.
The value of v is close to :
(Speed of sound in water = 1500 ms‌–1)
[12 April 2019 I]
A submarine (A) travelling at 18 km/hr is being chased along the line of its velocity by another submarine (B) travelling at 27 km/hr. B sends a sonar signal of 500 Hz to detect A and receives a reflected sound of frequency v.
The value of v is close to :
(Speed of sound in water = 1500 ms‌–1)
[12 April 2019 I]
Q.100 Correct
Q.100 In-correct
Q.100 Unattempt
Two sources of sound S1 and S2 produce sound waves of same frequency 660Hz. A listener is moving from source S1 towards S2 with a constant speed um∕s and he hears 10 beats/s. The velocity of sound is 330 m/s. Then u equals:
[12 April 2019 II]
Two sources of sound S1 and S2 produce sound waves of same frequency 660Hz. A listener is moving from source S1 towards S2 with a constant speed um∕s and he hears 10 beats/s. The velocity of sound is 330 m/s. Then u equals:
[12 April 2019 II]
Q.101 Correct
Q.101 In-correct
Q.101 Unattempt
A stationary source emits sounds waves of frequency 500 Hz. Two observers moving along a line passing through the source detect sound to be of frequencies 4801 Hz and 530 Hz. Their respective speeds are, in ms‌–1,
(Given speed of sound = 300 m/s)
[10 April 2019 I]
A stationary source emits sounds waves of frequency 500 Hz. Two observers moving along a line passing through the source detect sound to be of frequencies 4801 Hz and 530 Hz. Their respective speeds are, in ms‌–1,
(Given speed of sound = 300 m/s)
[10 April 2019 I]
Q.102 Correct
Q.102 In-correct
Q.102 Unattempt
A source of sound S is moving with a velocity of 50 m/s towards a stationary observer. The observer measures the frequency of the source as 1000 Hz. What will be the apparent frequency of the source when it is moving away from the observer after crossing him? (Take velocity of sound in air 350 m/s)
[10 April 2019 II]
A source of sound S is moving with a velocity of 50 m/s towards a stationary observer. The observer measures the frequency of the source as 1000 Hz. What will be the apparent frequency of the source when it is moving away from the observer after crossing him? (Take velocity of sound in air 350 m/s)
[10 April 2019 II]
Q.103 Correct
Q.103 In-correct
Q.103 Unattempt
Two cars A and B are moving away from each other in opposite directions. Both the cars are moving with a speed of 20 ms‌–1 with respect to the ground. If an observer in car A detects a frequency 2000 Hz of the sound coming from car B, what is the natural frequency of the sound source in car B?
(speed of sound in air = 340 ms‌–1)
[9 April 2019 II]
Two cars A and B are moving away from each other in opposite directions. Both the cars are moving with a speed of 20 ms‌–1 with respect to the ground. If an observer in car A detects a frequency 2000 Hz of the sound coming from car B, what is the natural frequency of the sound source in car B?
(speed of sound in air = 340 ms‌–1)
[9 April 2019 II]
Q.104 Correct
Q.104 In-correct
Q.104 Unattempt
A granite rod of 60 cm length is clamped at its middle point and is set into longitudinal vibrations. The density of granite is 2.7×103 kg/m‌3 and its Young's modulus is 9.27×1010 Pa.
What will be the fundamental frequency of the longitudinal vibrations?
[2018]
A granite rod of 60 cm length is clamped at its middle point and is set into longitudinal vibrations. The density of granite is 2.7×103 kg/m‌3 and its Young's modulus is 9.27×1010 Pa.
What will be the fundamental frequency of the longitudinal vibrations?
[2018]
Q.105 Correct
Q.105 In-correct
Q.105 Unattempt
The end correction of a resonance column is 1cm. If the shortest length resonating with the tuning fork is 10cm, the next resonating length should be
[Online April 16, 2018]
The end correction of a resonance column is 1cm. If the shortest length resonating with the tuning fork is 10cm, the next resonating length should be
[Online April 16, 2018]
Q.106 Correct
Q.106 In-correct
Q.106 Unattempt
A tuning fork vibrates with frequency 256 Hz and gives one beat per second with the third normal mode of vibration of an open pipe. What is the length of the pipe?
(Speed of sound of air is 340 ms‌–1 )
[Online April 15, 2018]
A tuning fork vibrates with frequency 256 Hz and gives one beat per second with the third normal mode of vibration of an open pipe. What is the length of the pipe?
(Speed of sound of air is 340 ms‌–1 )
[Online April 15, 2018]
Q.107 Correct
Q.107 In-correct
Q.107 Unattempt
5 beats/ second are heard when a turning fork is sounded with a sonometer wire under tension, when the length of the sonometer wire is either 0.95m or 1m . The frequency of the fork will be:
[Online April 15, 2018]
5 beats/ second are heard when a turning fork is sounded with a sonometer wire under tension, when the length of the sonometer wire is either 0.95m or 1m . The frequency of the fork will be:
[Online April 15, 2018]
Q.108 Correct
Q.108 In-correct
Q.108 Unattempt
Two sitar strings, A and B, playing the note 'Dha' are slightly out of tune and produce beats and frequency 5 Hz. The tension of the string B is slightly increased and the beat frequency is found to decrease by 3 Hz . If the frequency of A is 425 Hz, the original frequency of B is
[Online April 16, 2018]
Two sitar strings, A and B, playing the note 'Dha' are slightly out of tune and produce beats and frequency 5 Hz. The tension of the string B is slightly increased and the beat frequency is found to decrease by 3 Hz . If the frequency of A is 425 Hz, the original frequency of B is
[Online April 16, 2018]
Q.109 Correct
Q.109 In-correct
Q.109 Unattempt
Two wires W1 and W2 have the same radius r and respective densities rho1 and ρ2 such that ρ2=4ρ1. They are joined together at the point O, as shown in the figure. The combination is used as a sonometer wire and kept under tension T. The point O is midway between the two bridges. When a stationary waves is set up in the composite wire, the joint is found to be a node. The ratio of the number of antinodes formed in W1 to W2 is :

[Online April 8, 2017]
Two wires W1 and W2 have the same radius r and respective densities rho1 and ρ2 such that ρ2=4ρ1. They are joined together at the point O, as shown in the figure. The combination is used as a sonometer wire and kept under tension T. The point O is midway between the two bridges. When a stationary waves is set up in the composite wire, the joint is found to be a node. The ratio of the number of antinodes formed in W1 to W2 is :

[Online April 8, 2017]
Q.110 Correct
Q.110 In-correct
Q.110 Unattempt
A standing wave is formed by the superposition of two waves travelling in opposite directions. The transverse displacement is given by
y(x,t)=0.5‌sin(
5π
4
x) cos(200πt)
What is the speed of the travelling wave moving in the positive x direction ?
(x and t are in meter and second, respectively.)
[Online April 9, 2017]
A standing wave is formed by the superposition of two waves travelling in opposite directions. The transverse displacement is given by
y(x,t)=0.5‌sin(
5π
4
x) cos(200πt)
What is the speed of the travelling wave moving in the positive x direction ?
(x and t are in meter and second, respectively.)
[Online April 9, 2017]
Q.111 Correct
Q.111 In-correct
Q.111 Unattempt
A uniform string of length 20 m is suspended from a rigid support. A short wave pulse is introduced at its lowest end. It starts moving up the string. The time taken to reach the supports is :(take g = 10 ms‌–2)
[2016]
A uniform string of length 20 m is suspended from a rigid support. A short wave pulse is introduced at its lowest end. It starts moving up the string. The time taken to reach the supports is :(take g = 10 ms‌–2)
[2016]
Q.112 Correct
Q.112 In-correct
Q.112 Unattempt
A pipe open at both ends has a fundamental frequency f in air. The pipe is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is now :
[2016]
A pipe open at both ends has a fundamental frequency f in air. The pipe is dipped vertically in water so that half of it is in water. The fundamental frequency of the air column is now :
[2016]
Q.113 Correct
Q.113 In-correct
Q.113 Unattempt
A toy–car, blowing its horm, is moving with a steady speed of 5 m/s, away from a wall. An observer, towards whom the toy car is moving, is able to hear 5 beats per second. If the velocity of sound in air is 340 m/s, the frequency of the horn of the toy car is close to :
[Online April 10, 2016]
A toy–car, blowing its horm, is moving with a steady speed of 5 m/s, away from a wall. An observer, towards whom the toy car is moving, is able to hear 5 beats per second. If the velocity of sound in air is 340 m/s, the frequency of the horn of the toy car is close to :
[Online April 10, 2016]
Q.114 Correct
Q.114 In-correct
Q.114 Unattempt
Two engines pass each other moving in opposite directions with uniform speed of 30 m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330 m/sec:
[Online April 9, 2016]
Two engines pass each other moving in opposite directions with uniform speed of 30 m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before they pass each other. Speed of sound is 330 m/sec:
[Online April 9, 2016]
Q.115 Correct
Q.115 In-correct
Q.115 Unattempt
A train is moving on a straight track with speed 20 ms‌–1. It is blowing its whistle at the frequency of 1000 Hz. The percentage change in the frequency heard by a person standing near the track as the train passes him is (speed of sound = 320 ms‌–1) close to :
[2015]
A train is moving on a straight track with speed 20 ms‌–1. It is blowing its whistle at the frequency of 1000 Hz. The percentage change in the frequency heard by a person standing near the track as the train passes him is (speed of sound = 320 ms‌–1) close to :
[2015]
Q.116 Correct
Q.116 In-correct
Q.116 Unattempt
A source of sound emits sound waves at frequency f0. It is moving towards an observer with fixed speed vs(vs<v, where v is the speed of sound in air). If the observer were to move towards the source with speed v0, one of the following two graphs (A and B) will given the correct variation of the frequency f heard by the observer as v0 is changed.
The variation of f with v0 is given correctly by :
[Online April 11, 2015]
A source of sound emits sound waves at frequency f0. It is moving towards an observer with fixed speed vs(vs<v, where v is the speed of sound in air). If the observer were to move towards the source with speed v0, one of the following two graphs (A and B) will given the correct variation of the frequency f heard by the observer as v0 is changed.

The variation of f with v0 is given correctly by :
[Online April 11, 2015]
Q.117 Correct
Q.117 In-correct
Q.117 Unattempt
A bat moving at 10 ms‌–1 towards a wall sends a sound signal of 8000 Hz towards it. On reflection it hears a sound of frequency f. The value of f in Hz is close to (speed of sound = 320 ms‌–1)
[Online April 10, 2015]
A bat moving at 10 ms‌–1 towards a wall sends a sound signal of 8000 Hz towards it. On reflection it hears a sound of frequency f. The value of f in Hz is close to (speed of sound = 320 ms‌–1)
[Online April 10, 2015]
Q.118 Correct
Q.118 In-correct
Q.118 Unattempt
A transverse wave is represented by
y=
10
π
‌sin(
2π
T
t−
2π
λ
x)
For what value of the wavelength the wave velocity is twice the maximum particle velocity?
[Online April 9, 2014]
A transverse wave is represented by
y=
10
π
‌sin(
2π
T
t−
2π
λ
x)
For what value of the wavelength the wave velocity is twice the maximum particle velocity?
[Online April 9, 2014]
Q.119 Correct
Q.119 In-correct
Q.119 Unattempt
A pipe of length 85 cm is closed from one end. Find the number of possible natural oscillations of air column in the pipe whose frequencies lie below 1250 Hz. The velocity of sound in air is 340 m/s.
[2014]
A pipe of length 85 cm is closed from one end. Find the number of possible natural oscillations of air column in the pipe whose frequencies lie below 1250 Hz. The velocity of sound in air is 340 m/s.
[2014]
Q.120 Correct
Q.120 In-correct
Q.120 Unattempt
The total length of a sonometer wire between fixed ends is 110 cm. Two bridges are placed to divide the length of wire in ratio 6 : 3 : 2. The tension in the wire is 400 N and the mass per unit length is 0.01 kg/m. What is the minimum common frequency with which three parts can vibrate?
[Online April 19, 2014]
The total length of a sonometer wire between fixed ends is 110 cm. Two bridges are placed to divide the length of wire in ratio 6 : 3 : 2. The tension in the wire is 400 N and the mass per unit length is 0.01 kg/m. What is the minimum common frequency with which three parts can vibrate?
[Online April 19, 2014]
Q.121 Correct
Q.121 In-correct
Q.121 Unattempt
A source of sound A emitting waves of frequency 1800 Hz is falling towards ground with a terminal speed v. The observer B on the ground directly beneath the source receives waves of frequency 2150 Hz. The source A receives waves, reflected from ground of frequency nearly: (Speed of sound = 343 m/s)
[Online April 12, 2014]
A source of sound A emitting waves of frequency 1800 Hz is falling towards ground with a terminal speed v. The observer B on the ground directly beneath the source receives waves of frequency 2150 Hz. The source A receives waves, reflected from ground of frequency nearly: (Speed of sound = 343 m/s)
[Online April 12, 2014]
Q.122 Correct
Q.122 In-correct
Q.122 Unattempt
Two factories are sounding their sirens at 800 Hz. A man goes from one factory to other at a speed of 2m/s. The velocity of sound is 320 m/s. The number of beats heard by the person in one second will be:
[Online April 11, 2014]
Two factories are sounding their sirens at 800 Hz. A man goes from one factory to other at a speed of 2m/s. The velocity of sound is 320 m/s. The number of beats heard by the person in one second will be:
[Online April 11, 2014]
Q.123 Correct
Q.123 In-correct
Q.123 Unattempt
A sonometer wire of length 1.5 m is made of steel. The tension in it produces an elastic strain of 1%. What is the fundamental frequency of steel if density and elasticity of steel are 7.7×103 kg/m‌3 and 2.2×1011 N/m‌2 respectively?
[2013]
A sonometer wire of length 1.5 m is made of steel. The tension in it produces an elastic strain of 1%. What is the fundamental frequency of steel if density and elasticity of steel are 7.7×103 kg/m‌3 and 2.2×1011 N/m‌2 respectively?
[2013]
Q.124 Correct
Q.124 In-correct
Q.124 Unattempt
In a transverse wave the distance between a crest and neighbouring trough at the same instant is 4.0cm and the distance between a crest and trough at the same place is 1.0cm. The next crest appears at the same place after a time interval of 0.4 s. The maximum speed of the vibrating particles in the medium is:
[Online April 25, 2013]
In a transverse wave the distance between a crest and neighbouring trough at the same instant is 4.0cm and the distance between a crest and trough at the same place is 1.0cm. The next crest appears at the same place after a time interval of 0.4 s. The maximum speed of the vibrating particles in the medium is:
[Online April 25, 2013]
Q.125 Correct
Q.125 In-correct
Q.125 Unattempt
When two sound waves travel in the same direction in a medium, the displacements of a particle located at 'x' at time ‘t’ is given by :
y1=0.05‌cos(0.50πx−100πt)
y2=0.05‌cos(0.46πx−92πt)
where y1,y2 and x are in meters and t in seconds. The speed of sound in the medium is :
[Online April 9, 2013]
When two sound waves travel in the same direction in a medium, the displacements of a particle located at 'x' at time ‘t’ is given by :
y1=0.05‌cos(0.50πx−100πt)
y2=0.05‌cos(0.46πx−92πt)
where y1,y2 and x are in meters and t in seconds. The speed of sound in the medium is :
[Online April 9, 2013]
Q.126 Correct
Q.126 In-correct
Q.126 Unattempt
A sonometer wire of length 114 cm is fixed at both the ends.
Where should the two bridges be placed so as to divide the wire into three segments whose fundamental frequencies are in the ratio 1 : 3 : 4 ?
[Online April 23, 2013]
A sonometer wire of length 114 cm is fixed at both the ends.
Where should the two bridges be placed so as to divide the wire into three segments whose fundamental frequencies are in the ratio 1 : 3 : 4 ?
[Online April 23, 2013]
Q.127 Correct
Q.127 In-correct
Q.127 Unattempt
A and B are two sources generating sound waves. A listener is situated at C. The frequency of the source at A is 500 Hz. A, now, moves towards C with a speed 4 m/s. The number of beats heard at C is 6. When A moves away from C with speed 4 m/s, the number of beats heard at C is 18. The speed of sound is 340 m/s. The frequency of the source at B is :

[Online April 22, 2013]
A and B are two sources generating sound waves. A listener is situated at C. The frequency of the source at A is 500 Hz. A, now, moves towards C with a speed 4 m/s. The number of beats heard at C is 6. When A moves away from C with speed 4 m/s, the number of beats heard at C is 18. The speed of sound is 340 m/s. The frequency of the source at B is :

[Online April 22, 2013]
Q.128 Correct
Q.128 In-correct
Q.128 Unattempt
An engine approaches a hill with a constant speed. When it is at a distance of 0.9 km, it blows a whistle whose echo is heard by the driver after 5 seconds. If the speed of sound in air is 330 m/s, then the speed of the engine is :
[Online April 9, 2013]
An engine approaches a hill with a constant speed. When it is at a distance of 0.9 km, it blows a whistle whose echo is heard by the driver after 5 seconds. If the speed of sound in air is 330 m/s, then the speed of the engine is :
[Online April 9, 2013]
Q.129 Correct
Q.129 In-correct
Q.129 Unattempt
Following are expressions for four plane simple harmonic waves
(i) y1=A‌cos‌2‌π(n1t+
x
λ1
)
(ii) y2=A‌cos‌2‌π(n1t+
x
λ1
+π)
(iii) y3=A‌cos‌2‌π(n2t+
x
λ2
)
(iv) y4=A‌cos‌2‌π(n2t−
x
λ2
)
The pairs of waves which will produce destructive interference and stationary waves respectively in a medium, are
[Online May 7, 2012]
Following are expressions for four plane simple harmonic waves
(i) y1=A‌cos‌2‌π(n1t+
x
λ1
)
(ii) y2=A‌cos‌2‌π(n1t+
x
λ1
+π)
(iii) y3=A‌cos‌2‌π(n2t+
x
λ2
)
(iv) y4=A‌cos‌2‌π(n2t−
x
λ2
)
The pairs of waves which will produce destructive interference and stationary waves respectively in a medium, are
[Online May 7, 2012]
Q.130 Correct
Q.130 In-correct
Q.130 Unattempt
The disturbance y(x,t) of a wave propagating in the positive x -direction is given by y=
1
1+x2
 at time t=0 and by y=
1
[1+(x−1)2]
 at t=2s, where x and y are in meters. The shape of the wave disturbance does not change during the propagation. The velocity of wave in m∕s is
[Online May 26, 2012]
The disturbance y(x,t) of a wave propagating in the positive x -direction is given by y=
1
1+x2
 at time t=0 and by y=
1
[1+(x−1)2]
 at t=2s, where x and y are in meters. The shape of the wave disturbance does not change during the propagation. The velocity of wave in m∕s is
[Online May 26, 2012]
Q.131 Correct
Q.131 In-correct
Q.131 Unattempt
A cylindrical tube, open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of the air-column is now :
[2012]
A cylindrical tube, open at both ends, has a fundamental frequency f in air. The tube is dipped vertically in water so that half of it is in water. The fundamental frequency of the air-column is now :
[2012]
Q.132 Correct
Q.132 In-correct
Q.132 Unattempt
An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork of frequency 264 Hz if the length of the column in cm is (velocity of sound = 330 m/s)
[Online May 26, 2012]
An air column in a pipe, which is closed at one end, will be in resonance with a vibrating tuning fork of frequency 264 Hz if the length of the column in cm is (velocity of sound = 330 m/s)
[Online May 26, 2012]
Q.133 Correct
Q.133 In-correct
Q.133 Unattempt
A uniform tube of length 60.5 cm is held vertically with its lower end dipped in water. A sound source of frequency 500 Hz sends sound waves into the tube. When the length of tube above water is 16 cm and again when it is 50 cm, the tube resonates with the source of sound. Two lowest frequencies (in Hz), to which tube will resonate when it is taken out of water, are (approximately).
[Online May 19, 2012]
A uniform tube of length 60.5 cm is held vertically with its lower end dipped in water. A sound source of frequency 500 Hz sends sound waves into the tube. When the length of tube above water is 16 cm and again when it is 50 cm, the tube resonates with the source of sound. Two lowest frequencies (in Hz), to which tube will resonate when it is taken out of water, are (approximately).
[Online May 19, 2012]
Q.134 Correct
Q.134 In-correct
Q.134 Unattempt
A wave represented by the equation y1=a‌cos(kx−ωt) is superimposed with another wave to form a stationary wave such that the point x−0 is node. The equation for the other wave is
[Online May 12, 2012]
A wave represented by the equation y1=a‌cos(kx−ωt) is superimposed with another wave to form a stationary wave such that the point x−0 is node. The equation for the other wave is
[Online May 12, 2012]
Q.135 Correct
Q.135 In-correct
Q.135 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: Bats emitting ultrasonic waves can detect the location of a prey by hearing the waves reflected from it.
Statement 2: When the source and the detector are moving, the frequency of reflected waves is changed.
[Online May 12, 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: Bats emitting ultrasonic waves can detect the location of a prey by hearing the waves reflected from it.
Statement 2: When the source and the detector are moving, the frequency of reflected waves is changed.
[Online May 12, 2012]
Q.136 Correct
Q.136 In-correct
Q.136 Unattempt
The transverse displacement y(x,t) of a wave is given by y(x,t)=e−(ax2+bt2+2√ab)xt)This represents a :
[2011]
The transverse displacement y(x,t) of a wave is given by y(x,t)=e−(ax2+bt2+2√ab)xt)This represents a :
[2011]
Q.137 Correct
Q.137 In-correct
Q.137 Unattempt
A travelling wave represented by y=A‌sin(ωt−kx) is superimposed on another wave represented by y=A‌sin(ωt+kx). The resultant is
[2011 RS]
A travelling wave represented by y=A‌sin(ωt−kx) is superimposed on another wave represented by y=A‌sin(ωt+kx). The resultant is
[2011 RS]
Q.138 Correct
Q.138 In-correct
Q.138 Unattempt
Statement - 1 : Two longitudinal waves given by equations: y1(x,t)=2a‌sin(ωt−kx) and y2(x,t)=a sin(2ωt−2kx) will have equal intensity.
Statement - 2 : Intensity of waves of given frequency in same medium is proportional to square of amplitude only.
[2011 RS]
Statement - 1 : Two longitudinal waves given by equations: y1(x,t)=2a‌sin(ωt−kx) and y2(x,t)=a sin(2ωt−2kx) will have equal intensity.
Statement - 2 : Intensity of waves of given frequency in same medium is proportional to square of amplitude only.
[2011 RS]
Q.139 Correct
Q.139 In-correct
Q.139 Unattempt
The equation of a wave on a string of linear mass density 0.04 kg m‌–1 is given by
y=0.02(m)‌sin [2π(
t
0.04(s)
−
x
0.50(m)
)]
The tension in the string is
[2010]
The equation of a wave on a string of linear mass density 0.04 kg m‌–1 is given by
y=0.02(m)‌sin [2π(
t
0.04(s)
−
x
0.50(m)
)]
The tension in the string is
[2010]
Q.140 Correct
Q.140 In-correct
Q.140 Unattempt
Three sound waves of equal amplitudes have frequencies (ν−1),ν,(ν+1) . They superpose to give beats. The number of beats produced per second will be :
[2009]
Three sound waves of equal amplitudes have frequencies (ν−1),ν,(ν+1) . They superpose to give beats. The number of beats produced per second will be :
[2009]
Q.141 Correct
Q.141 In-correct
Q.141 Unattempt
A motor cycle starts from rest and accelerates along a straight path at 2m/s‌2 . At the starting point of the motor cycle there is a stationary electric siren. How far has the motor cycle gone when the driver hears the frequency of the siren at 94% of its value when the motor cycle was at rest? (Speed of sound = 330 ms‌–1)
[2009]
A motor cycle starts from rest and accelerates along a straight path at 2m/s‌2 . At the starting point of the motor cycle there is a stationary electric siren. How far has the motor cycle gone when the driver hears the frequency of the siren at 94% of its value when the motor cycle was at rest? (Speed of sound = 330 ms‌–1)
[2009]
Q.142 Correct
Q.142 In-correct
Q.142 Unattempt
A wave travelling along the x -axis is described by the equation y(x,t)=0.005‌cos(αx−βt). If the wavelength and the time period of the wave are 0.08m and 2.0s, respectively, then α and β in appropriate units are
[2008]
A wave travelling along the x -axis is described by the equation y(x,t)=0.005‌cos(αx−βt). If the wavelength and the time period of the wave are 0.08m and 2.0s, respectively, then α and β in appropriate units are
[2008]
Q.143 Correct
Q.143 In-correct
Q.143 Unattempt
While measuring the speed of sound by performing a resonance column experiment, a student gets the first resonance condition at a column length of 18 cm during winter. Repeating the same experiment during summer, she measures the column length to be x cm for the second resonance. Then
[2008]
While measuring the speed of sound by performing a resonance column experiment, a student gets the first resonance condition at a column length of 18 cm during winter. Repeating the same experiment during summer, she measures the column length to be x cm for the second resonance. Then
[2008]
Q.144 Correct
Q.144 In-correct
Q.144 Unattempt
A sound absorber attenuates the sound level by 20 dB.
The intensity decreases by a factor of
[2007]
A sound absorber attenuates the sound level by 20 dB.
The intensity decreases by a factor of
[2007]
Q.145 Correct
Q.145 In-correct
Q.145 Unattempt
A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is
[2006]
A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then, the lowest resonant frequency for this string is
[2006]
Q.146 Correct
Q.146 In-correct
Q.146 Unattempt
A whistle producing sound waves of frequencies 9500 HZ and above is approaching a stationary person with speed v ms−1. The velocity of sound in air is 300ms−1. If the person can hear frequencies upto a maximum of 10,000HZ, the maximum value of v upto which he can hear whistle is
[2006]
A whistle producing sound waves of frequencies 9500 HZ and above is approaching a stationary person with speed v ms−1. The velocity of sound in air is 300ms−1. If the person can hear frequencies upto a maximum of 10,000HZ, the maximum value of v upto which he can hear whistle is
[2006]
Q.147 Correct
Q.147 In-correct
Q.147 Unattempt
When two tuning forks (fork 1 and fork 2) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2. When the tuning forks are sounded again, 6 beats per second are heard. If the frequency of fork 1 is 200 Hz, then what was the original frequency of fork 2?
[2005]
When two tuning forks (fork 1 and fork 2) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2. When the tuning forks are sounded again, 6 beats per second are heard. If the frequency of fork 1 is 200 Hz, then what was the original frequency of fork 2?
[2005]
Q.148 Correct
Q.148 In-correct
Q.148 Unattempt
An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency ?
[2005]
An observer moves towards a stationary source of sound, with a velocity one-fifth of the velocity of sound. What is the percentage increase in the apparent frequency ?
[2005]
Q.149 Correct
Q.149 In-correct
Q.149 Unattempt
The displacement y of a particle in a medium can be expressed as, y=10−6‌sin(100t+20x+
π
4
)‌m where t is in second and x in meter. The speed of the wave is
[2004]
The displacement y of a particle in a medium can be expressed as, y=10−6‌sin(100t+20x+
π
4
)‌m where t is in second and x in meter. The speed of the wave is
[2004]
Q.150 Correct
Q.150 In-correct
Q.150 Unattempt
The displacement y of a wave travelling in the x -direction is given by y=10−4‌sin(600t−2x+
π
3
) metres where x is expressed in metres and tin seconds. The speed of the wave - motion, in ms−1, is
[2003]
The displacement y of a wave travelling in the x -direction is given by y=10−4‌sin(600t−2x+
π
3
) metres where x is expressed in metres and tin seconds. The speed of the wave - motion, in ms−1, is
[2003]
Q.151 Correct
Q.151 In-correct
Q.151 Unattempt
A tuning fork of known frequency 256 Hz makes 5 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was
[2003]
A tuning fork of known frequency 256 Hz makes 5 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was
[2003]
Q.152 Correct
Q.152 In-correct
Q.152 Unattempt
When temperature increases, the frequency of a tuning fork
[2002]
When temperature increases, the frequency of a tuning fork
[2002]
Q.153 Correct
Q.153 In-correct
Q.153 Unattempt
Tube A has both ends open while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube A and B is
[2002]
Tube A has both ends open while tube B has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube A and B is
[2002]
Q.154 Correct
Q.154 In-correct
Q.154 Unattempt
A wave y=a‌sin(ωt−kx) on a string meets with another wave producing a node at x=0. Then the equation of the unknown wave is
[2002]
A wave y=a‌sin(ωt−kx) on a string meets with another wave producing a node at x=0. Then the equation of the unknown wave is
[2002]
Q.155 Correct
Q.155 In-correct
Q.155 Unattempt
A tuning fork arrangement (pair) produces 4 beats/sec with one fork of frequency 288 cps. A little wax is placed on the unknown fork and it then produces 2 beats/sec. Thefrequency of the unknown fork is
[2002]
A tuning fork arrangement (pair) produces 4 beats/sec with one fork of frequency 288 cps. A little wax is placed on the unknown fork and it then produces 2 beats/sec. Thefrequency of the unknown fork is
[2002]
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