MHT CET 2022 Physics question
A photon of energy 'E' ejects photoelectrons from a metal surface whose work function is . If this electron enters into uniform magnetic field of induction 'B' in a direction perpendicular to field and describes a circular path of radius 'r', then radius is given by
Answer: (B)
Solution
By Einstein's photoelectric equation the maximum kinetic energy of the photoelectron is , so . In the perpendicular magnetic field the magnetic force provides the centripetal force: , giving
See the full step-by-step solution
Create a free account to read the complete working, and practise questions like this in a timed test.
Create a free account