Give example of production of (i) electron by a photon and (ii) photon by an electron

Explanation

(i) When photon is incident on metal surface, electron is emitted in photoelectric effect.
(ii) In the process of production of X-rays, when high speed electrons in cathode rays are incident on a metal surface, X-ray photon is emitted.
(Hence photoelectric effect and X-ray production are two opposite effects)