Physics

Problem

A metallic surface is illuminated with radiation of wavelength

\lambda

, the stopping potential is

V_0

. If the same surface is illuminated with radiation of wavelength

2\lambda

, the stopping potential becomes

\frac{V_0}{4}

. The threshold wavelength for this metallic surface will be - (a)

\frac{\lambda}{4}

(b)

4\lambda

(c)

\frac{3}{2}\lambda

(d)

3\lambda