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)neI_(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

From graphs, we note that the stopping potential for curves a and b is same. Hence `f_(a)=f_(b)`. As saturation current is proportional to intensity of incident radiation. Therefore, `I_(a) lt I_(b)`. Hence, the option (a) is correct