For a particular frequency
of incident radiation, the minimum
negative (retarding) potential V0 given to
the plate A for which the photocurrent
stops or becomes zero is called the cut-
off or stopping potential in The interpretation of the observation
terms 
of 
photoelectrons 
is
straightforward All the photoelectrons
emitted from the metal do not have the
FIGURE 11 2 Variation of
Photoelectric current with
intensity of light