The figure shows a plot of photo current 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
• Correct answer
  B

  Curves $a$ and $b$ represent incident radiations of 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

Solution

From the two graphs we can conclude that for the graph in question curves $a$ and $b$ represent incident radiations of same frequency but of different intensities.

Hence, the correct answer is option: 'B'.