The fig. shows the variation of photon current with anode potential for a photo-sensitive surface for three different radiation. Let `I_(a), I_(b) and I_(c)` be the intensities and `f_(a), f_(b) and f_(c)` be the frequency for the curves a,b and c respectively.

Options

A. `f_a = f_b and I_a ne I_b`
B. `f_a = f_c and I_a = I_c`
C. `f_a = f_b and I_a = I_b`
D. `f_b = f_c and I_b = I_c`

Answer

A

Explanation

Stopping potential depends on frequency and in the given graph , we can see that stopping potential is same for graph a and b , hence we can say that `f_a =f_b` Saturation current for graphs a and b is different and hence intensity for graphs a must be different from that for graph b .
From above discussion , we can understand that option (a) is correct