Problem

Maximum kinetic energy of a photoelectron is

E

when the wavelength of incident light is

\lambda

. If energy becomes four times when wavelength is reduced to one-third, then work-function of the metal is a.

\frac{3hc}{\lambda}

\frac{hc}{3\lambda}

\frac{hc}{\lambda}

\frac{hc}{2\lambda}