Answer to Question #86894 in Electric Circuits for VIKASH KUMAR

Question

On the basis of their biasing, with the help of appropriate diagrams, justify the uses
of Class A, AB and C amplifiers for various applications.

Answer 1

Class A amplifier is very simple and and uses one transistor in CE biasing configuration and produces inverted output. It is always ON-biased, and the output signal has low distortion. The diagram is shown below in comparison with AB amplifier:

Class AB amplifier is constructed almost as class A amplifier, but due to pre-biasing two transistors in the output stage it can provide higher output currents. The distortion is low.

In class C amplifier transistor works (conducts) for less than one half of the cycle of the input signal. The output signal thus is have high distortion and these amplifiers are not used in audio appliances.