Question

When light of wavelength 300 nm (nanometer) falls on a photoelectric emitter, photoelectrons are liberated. For another emitter, however light of 600nm wavelength is sufficient for creating photoemission. What is the ratio of the work functions of the two emitters?

• A. 1 : 2
• B. 2 : 1
• C. 4 : 1
• D. 1 : 4

Answer 1

Answer: (B)

2 : 1

Answer 2

W = hn₀ = hc/l₀

= $\frac { \lambda _ { 02 } } { \lambda _ { 01 } }$ = $\frac { 600 } { 300 }$ = 2 : 1