Thus, the plate A can be maintained at a desired
positive or negative potential with respect to emitter C When the collector plate A is positive with respect to the
emitter plate C, the electrons are attracted to it The
emission of electrons causes flow of electric current in
the circuit The potential difference between the emitter
and collector plates is measured by a voltmeter (V)
whereas the resulting photo current flowing in the circuit
is measured by a microammeter (mA)