Question

The figure shows a plot of photocurrent versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement?

• A. Curves $a$ and $b$ represent incident radiations of different frequencies and different intensities
• B. Curves $a$ and $b$ represent incident radiations of the same frequency but of different intensities
• C. Curves $b$ and $c$ represent incident radiations of different frequencies and different intensities
• D. Curves $b$ and $c$ represent incident radiations of same frequency having same intensity

Answer 1

The correct option is B Curves $a$ and $b$ represent incident radiations of the same frequency but of different intensities


From the graph, the retarding potential is equal of curves $a$ and $b$, therefore their frequency is same.

Also, their photocurrents are different, therefore they have different intensities.

​​​​​​​Hence, option $\left(B\right)$ is the correct answer.