Question

Transistor as an Oscillator.

Answer 1

A transistor can be used as an oscillator.

An oscillator generates ac output signal without any input ac signal. An oscillator is a self sustained amplifier in which a part of output is fed back to the input in the same phase (called positive feedback).

The block diagram of an oscillator is shown in the figure

The circuit diagram of the tuned collector oscillator is shown in the figure below.

The frequency of the oscillation is given by

$\upsilon = \frac{1}{2\pi\sqrt{LC}}$