Question

In Compton scattering, if the incident photon has a wavelength of 0.2 nm and Φ = 90°, the angle at which recoil electron appears is ___________

(a) 30.12°

(b) 38.46°

(c) 44.57°

(d) 53.12°

This question was posed to me in an international level competition.

The doubt is from X-Rays and Compton Effect in section X-Rays and Compton Effect of Engineering Physics II

Answer 1

The correct choice is (c) 44.57°

Easy explanation: We know, tanθ = \(\frac{\lambda sin⁡\Phi}{\lambda^{‘}-\lambda cos⁡\Phi}\)

= 2 X 10^-10/(2.204 – 2) X 10^-10

= 2/2.024

= 0.9980

Θ = tan^-10.9980

= 44.57°.