MOSFET
Symbol
There is also a
symbol for this type of transistors. This symbol resembles
the one for the point-contact transistor but they are not
identical. The names of the electrodes also differ. In the
FET the electrodes are called source-gate-drain and as you
might remember they are called emitter-base-collector in
the point-contact transistor.
Both the
point-contact transistor and the MOSFET can be used for the
same purposes. The two main uses of any transistor are as a
modulator/amplifier and as a switch.