# From this figure describing photoelectric effect, we may infer correctly that :

$\begin {array} {1 1} (A)\;\text{$Na$and$Al$both have same threshold frequency}\\ (B)\;\text{maximum$K.E$for both the metals depend linearly on the frequency} \\ (C)\;\text{the stopping potentials are different for$Na$and$Al$for the same change in frequency} \\ (D)\;\text{$Al$is a more photosensitive material than$Na$} \end {array}$

Ans : (b)
Since, stopping potential, $V_{\circ},\: ; eV_{\circ} = K.E_{max}$
i.e.,$V_{\circ}$ is directly proportional to $K.E_{max}$

edited Mar 13, 2014