Question

When light of wavelength ‘λ’ is incident on photosensitive surface, the stopping potential is

‘V’. When light of wavelength ‘3λ’ is incident on same surface, the stopping potential is

'V'

6 . Threshold wavelength for the surface is



Any one the solution???​

Answer 1

Answer : (b) 4λ

Explanation :

Einstein's photoelectric equation :

hcλ=e(3V0)+W−−−−(1)

Here W=work function ; and hcλ=e(V0)+W−−−−(2)

Solving equations

(1)-(2)

hcλ=3hc2λ−W−3W

2W=hc2λ

hcλ0=hc4π

λ0=4λwhenλ0= threshold wavelength