The Total solution for NCERT class 6-12
Light of frequency 7.21 × 1014 Hzis incident on a metal surface. Electrons with a maximum speed of 6.0 × 105 m/sare ejected from the surface. What is the threshold frequency for photoemissionof electrons?
Frequency of the incident photon,
Maximum speed of the electrons, v =6.0 × 105 m/s
Planck’s constant, h =6.626 × 10−34 Js
Mass of an electron, m =9.1 × 10−31 kg
For threshold frequency ν0,the relation for kinetic energy is written as:
Therefore, the threshold frequency for thephotoemission of electrons is