question_answer

When 1 cm thick surface is illuminated with light of wavelength \[250\times {{10}^{-3}}m/s\], the stopping potential is V. When the same surface is illuminated by light of wavelength \[25\times {{10}^{-3}}m/s\], the stopping potential is \[2.50\times {{10}^{-3}}m/s\]. Threshold wavelength for metallic surface is

A)  \[1.25\times {{10}^{3}}m/s\]                    

B)  \[\frac{hv}{4}\]

C)   \[\frac{hv}{3}\]                              

D)  \[\frac{hv}{2}\]