Question

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

• A. 1:04
• B. 4:01
• C. 2:01
• D. 1:02

Answer 1

Answer: (C)

2:01

Answer 2

From the formula of work function ${{W}_{0}}=\frac{hc}{\lambda }$ here ${{\lambda }_{0}}$ is threshold wavelength $\frac{{{W}_{01}}}{{{W}_{02}}}=\frac{{{\lambda }_{02}}}{{{\lambda }_{01}}}=\frac{600}{300}=\frac{2}{1}$