Question

The rest mass of the photon is(a) 0(b) ∝(c) Between 0 and ∝
(d) Equal to that of an electron

Answer 1

(D) equal ............electron

Answer 2

The rest mass of a photon is zero .

OPTION A is the answer .

Details .

The photon is a light particle .

It is never at rest.

It is always in motion.

Hence rest energy is zero.

Put this in the Einstein's equation :

E² = m²c⁴ + p²c²

m²c⁴ = 0

But c is not 0 .

So mass has to be 0.