Question

The figure shows variation of photocurrent with anode potential for a photo-sensitive surface for three different radiations. Let $I_{a},I_{b}$ and $I_{c}$ be the intensities and $v_{a},v_{b}$ and $v_{c}$ be the frequencies for the curves $a,b$ and $c$ respectively. Then

• A. $v_{a}=v_{b} \, and \, I_{a}\neq I_{b}$
• B. $v_{a}=v_{c} \, and \, I_{a}=I_{c}$
• C. $v_{a}=v_{b} \, and \, \, I_{a}=I_{b}$
• D. $v_{b}=v_{c} \, and \, \, I_{b}=I_{c}$

Answer 1

Answer: (A)

Saturation current is proportional to intensity while stopping potential increases with increase in frequency. Hence,
$ \, \, v_{a}=v_{b}$ while $I_{a} < I_{b}$