The wavelength of an X-ray beam is
Question:

The wavelength of an X-ray beam is 10A The mass of a fictitious particle having the same

energy as that of the X-ray photons is $\frac{x}{3} \mathrm{~h} \mathrm{~kg}$.

The value of $x$ is__________.

$(h=$ Planck’s constant $)$

Solution:

$\frac{\mathrm{hc}}{\lambda}=\mathrm{mc}^{2}$

$\mathrm{m}=\frac{\mathrm{h}}{\mathrm{c} \lambda}$