Question

The figure shows the variation of photocurrent with anode potential for a photosensitive surface for three different radiations. Let $I_a,I_{b}and{I}_c$ be the intensities and $f_a,f_{b}and{f}_c$ be the frequencies for the curves a, b and c respectively

• 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 1

Answer: (A)

Saturation current is proportional to intensity while stopping potential increases with increase in frequency.
Hence, $f_a=f_b$ while I_a < I_b
Therefore, the correct option is (a).