The formula we' ll use is the Einstein's energy equation -

E= h v = hc/L where h is the Planck's constant, c is light wave velocity and L is the wavelength.

1 ev = 1.6 * 10

E= h v = hc/L where h is the Planck's constant, c is light wave velocity and L is the wavelength.

1 ev = 1.6 * 10

^{-19}J, c = 3*10^{8}For 2ev photon, L = 6.211 * 10^{-7}m, For X ray, L = 3.9756 * 10^{-10}m