Q.
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) $v_{b} = v_{c}and\ I_{b} = I_{c}$
Explanation
(a) Saturation current is proportional to intensity while stopping potential increases with increase in frequency. Hence,
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ v_{a} = v_{b}$ while $I_{a} < I_{b}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.