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).