Explanation:
The equation E = pc is valid for a particle with zero rest mass. The rest mass of a photon is zero, but the rest mass of an electron is not zero. So, the equation will be valid for photon, and not electron.
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When current in a coil changes to 2 ampere from 8 ampere in 3 
, the e.m.f. induced in the coil is 2 volt. The self inductance of the coil in millihenry is
|
(a) 1 |
(b) 5 |
(c) 20 |
(d) 10 |
An object 2.5 cm high is placed at a distance of 10 cm from a concave mirror of radius of curvature 30 cm The size of the image is
|
(a) 9.2 cm |
(b) 10.5 cm |
(c) 5.6 cm |
(d) 7.5 cm |
Two protons exerts a nuclear force on each other, the distance between them is
|
(a) |
(b) |
(c) |
(d) |
Assertion : NOT gate is also called inverter circuit.
Reason : NOT gate inverts the input order.
|
(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 reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
A heating coil can heat the water of a vessel from 20℃ to 60℃ in 30 minutes. Two such heating coils are put in series and then used to heat the same amount of water through the same temperature range. The time taken now will be (neglecting thermal capacity of the coils)
|
(a) 60 minutes |
(b) 30 minutes
|
(c) 15 minutes |
(d) 7.5 minutes |
The minimum temperature of a body at which it emits light is
|
(a) 1200°C |
(b) 1000°C |
(c) 500°C |
(d) 200°C |
