Question

The anode voltage of a photocell is kept fixed. The wavelength $\lambda$ of the light falling on the cathode is gradually changed. The plate current $I$ of photocell varies as follows

• A.
• B.
• C.
• D.

Answer 1

Answer: (D)

Answer 2

As $\lambda$ is increased, there will be a value of $\lambda$ above which photoelectron will cease to come out. So, photocurrent will be zero.