When an electron-positron pair annihilates, how much energy is released?

Directions: In the following question, a statement of Assertion is given, followed by a corresponding statement of Reason. Mark the correct answer as:

(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.

(b) If both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.

(c) If Assertion is true, but Reason is false.

(d) If both Assertion and Reason are false.

Assertion : Neutrons penetrate a matter more readily as compared to protons.

Reason : Neutrons are slightly more massive than protons.

If M0is the mass of an oxygen isotope 8O17, and Mp and Mn are the masses of a proton and a neutron, respectively, then what is the nuclear binding energy of the isotope

A shell at rest, at the origin explodes into three fragments of masses 1 kg, 2 kg and m kg. The pieces weighing 1 kg and 2 kg fly off with a speed of 5 ms–1along x– axis and 6 ms–1along y– axis respectively. If the 'm' kg piece flies off with a speed of 6.5 ms–1, what must be the total mass of the shell?

A nucleus decays by+emission, followed by-emission. If the atomic and mass numbers of the parent nucleus are Z and A, respectively, then the corresponding numbers for the daughter nucleus are

A heater wire consumes power `P` when connected to a 220V source. If the wire is cut into four equal pieces, which are now connected in parallel, find the power consumed by the combination, if connected to the same power supply.

Two electric bulbs rated P1watt V volt, and P2watt V volt are connected in parallel, and applied across V volt. The total power will be

If power dissipated by 5Ω resistor is 20 W, then find the power dissipated by 4Ω resistor.

The thermo emf produced in a thermocouple is 3μV/oC. If the temperature of the cold junction is 20oC and the thermo emf is 0.3 mV, the temperature of the hot junction is

Consider the followingtwo statements A and B and identify the correct answer.

A:Constantan-Copper thermo-couple is generally used to measure temperature upto 1600oC.

B:In an iron-copper thermocouple, current flows from iron to copper through cold junction.

If the forces of magnitude 12 Kg wt, 5 Kg wt and 13 Kg wt acting at a point are in equilibrium, then the angle between the two forces is

Two men carry a weight of 240 kg between them by means of two ropes fixed to the weight. One rope is inclined at 60× to the vertical and the other at 30×. The tensions in the ropes are

The resultant of P and Q is R. If P is reversed, Q remains the same, the new resultant S is at right angle to R. The value of P / Q is