What is a potentiometer?

What is potentiometer ? Explain principle of potentiometer.

What is potentiometer? Discuss its principle.

What is potentiometer ? Discuss its principle.

What is potentiometer ? Give its constant and principle.

What is potentiometer? With the help of circuit diagram, explain how a potentiometer can be used to compare the emf of two primary cells.

What is potentiometer?Would you prefer a voltmeter or a potentiometer to measure the e.m.f of a battery?