If in a photoelectric experiment, the wavelength of incident radiation is reduced from $6000\: A^{\circ} \: to \: 4000\: A^{\circ}$ , then

Question

(a) Stopping potential will decrease

(b) Stopping potential will increase

(c) KE of emitted electrons will decrease

(d) value of work function will decrease

Answer 1

Ans : (b)

$ \phi = \large\frac{hc}{ \lambda} - eV_{\circ} \phi =$ work function of a particular metal will remain constant

If $\lambda$ = incident radiation wavelength is increased,

$ V_{\circ}$ = stopping potential also has to increase to keep $ \phi$ constant.