What Is A Potentiometer And Give Information About Its Use?

A potentiometer is a simple instrument which is used to measure correct value of electric potential difference in an electrical circuit. Usually, voltmeter is used to measure value or potential difference across any branch of electric circuit. By doing so a small current is drawn by voltmeter from the branch of the circuit.

This changes the value of electric current flowing in the branch. This shows connection of a voltmeter parallel to a branch of electric circuit does not give the correct value of potential difference across it. To remove this difficulty we must use a voltmeter of infinite resistance so that it may not draw any current from the branch of circuit when connected parallel to branch of circuit.

The voltmeter with its infinite resistance, to give correct value of potential difference is called; vacuum tube voltmeter there is another such device, for correct measurement of potential difference, which is called oscilloscope. These two instruments are too expensive to be used in laboratory measurement. Potentiometer is cheaper instrument which is easily affordable and by using it we can get correct measurement of voltage, because this instrument does not draw any current from the branch across which it is connected.