Compton scattering — UPSC Physics Optional CSE 1993 Paper II

With incident X-rays of wavelength 1.618\text{ \AA} Compton scattering is observed at 90^\circ from the incident beam. Calculate. (i) the wavelength of Compton radiation, and (ii) the angle at which the recoil electron may be observed. In what state should the electrons be in Compton scattering?