Question

When does the photocurrent become zero as negative potential is applied to the collector plate?

Options

• When even the fastest photoelectrons cannot reach the collector

• When all emitted photoelectrons are collected by the anode

• When the collector plate is made more positive

• When the intensity of incident light increases

Answer 1

At a sufficiently large negative potential, even the fastest photoelectrons are stopped. None reach the collector, so the photocurrent becomes zero.