Question

A material particle with a rest mass ${}^{\prime }{m}_0{}^{\prime }$ is moving with speed of light 'c'. The de-Broglie wavelength associated is given by

Answer 1

Theory of special relativity

$m^{\prime }=\gamma m=\frac{m}{\sqrt{1-\frac{V^2}{c^2}}}$

Debroglie wavelength

$\lambda =\frac{h}{m^{\prime }v}=\frac{h\sqrt{1-\frac{V^2}{c^2}}}{mv}$

If $v=c$
then $\lambda =0$