Question

Draw graphs showing variation of photoelectric current with applied voltage for two incident radiations of equal frequency and different intensities. Mark the graph for the radiation of higher intensity.

Answer 1

The graph I₂ corresponds to radiation of higher intensity [Note: Deduct this ½ mark if the student does not show the two graphs starting from the same point.] (Also accept if the student just puts some indicative marks, or words, (like tick, cross, higher intensity) on the graph itself.

Detailed Answer : 

The graph between photo electric current i and applied voltage V of equal frequency and different intensity I₁ and I₂, where I₂ > I₁, dark line shows higher intensity.