Sketch the graphs, showing the variation of stopping potential `V_s` with frequency v of the incident radiations for two photosensitive materials A and B having threshold frequencies `v_0gtv'_0` respectively.
(i) which of the two metals A or B has higher work function?
(ii) What information do you get from the slope of the graphs?
(iii) What does the value of the intercept of graph A on the potential axis represent?

Explanation

The variation of stopping potential `(V_s)` with frequency (v) of incident radiations for two photosenstive materials is shown in fig.

(i) Metal A has higher work function, as `phi_0 =hv_0 and phi'_0=hv'_0, since v_0gtv'_0`.
(ii) Slope of `V_s-v` graph=`h//e`. [For discussion see conceptual problem 7]
(iii) Intercept of graph A on the potential axis `=-(phi_0)/e=-(hv_0)/e`