-->

Wave Optics

Question
CBSEENPH12038455

Light of wavelength 488 nm is produced by an argon laser which is used in the photoelectric effect. When light from this spectral line is incident on the emitter, the stopping (cut-off) potential of photoelectrons is 0.38 V. Find the work function of the material from which the emitter is made.

Solution

Given,
Wavelength of light, λ = 488 nm = 488 x 10–9 m
Stopping potential, V0 = 0.38V 

As,            eV0 = hv - ϕ0

             eV0 = hcλ-ϕ0

              ϕ0 = hcλ-eV0

                           = 6.63 × 10-34 × 3 × 108488 × 10-9 × 1.6 × 10-19-1.6 × 10-19 × 0.381.6 × 10-19

                      = (2.55 - 0.38) eV = 2.17 eV.

Some More Questions From Wave Optics Chapter