question_answer

A photoelectric surface is illuminated successively by monochromatic light of wavelengths \[\lambda \] and \[\frac{\lambda }{3}\]. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 time that in the first case, the work function of the surface is:                              [JEE ONLINE 10-04-2016]

A)             \[\frac{3hc}{\lambda }\]

B)             \[\frac{hc}{\lambda }\]

C)             \[\frac{hc}{3\lambda }\]

D)             \[\frac{hc}{2\lambda }\]

Correct Answer: D

Solution :

[d]                        .. (i)

.. (ii)

(Equating (i) & (ii))