can any1 plz tell me what are clipper circuits ....and how they work

 

A positive clipper circuit passes a positive input signal voltage below its threshold and outputs a constant voltage for an input signal voltage above its threshold. A negative clipper does the same thing for negative voltages.

It is often implemented with diodes.

It's effect on a sine wave is to flatten the peaks.

 

Clipper circuit consist of a diode and a resistor.
Depending upon the direction of the diode(forward of reversed biased),it acts as a open switch(reversed biased) or closed switch(forward biased).Which can clipp the positive or negative part of input signal at the output.
It is used in wave shaping, basically a rectifier circuit...msg

 

Can someone please give an example of a clipper circuit with its calculation?

 

My textbook has a section on them.

Have you opened your textbook? Have you read it?