Question

The cathode of a photoelectric cell is changed such that the work function changes from $W_1$ to $W_2 (W_2 > W_1).$ If the current before and after changes are $I_1$ and $I_2$, all other conditions remaining unchanged, then (assuming $h \upsilon > W_2$)

• A. $I_1=I_2$
• B. $I_1 < I_2$
• C. $I_1 > I_2$
• D. $I_1 < I_2 < 2I_1$

Answer 1

Answer: (A)

$I_1=I_2$

Answer 2

The work function has no effect on photoelectric current so long as $h \upsilon > W_0$. The photoelectric current is proportional to the intensity of incident light. Since there is no change in the intensity of light, hence $I_1=I_2.$