26-12-2017, 10:44 AM
A potentiometer is a device used to measure the potential difference in a circuit. We know that the potential difference is the amount of work done when carrying a load from one point to another. When there is a potential difference in a circuit, the current flows through the circuit. The potential difference unit is measured in volts. The potential difference of a circuit can be measured with a voltmeter.
A potentiometer consists of a long cable with a uniform area of cross section. In general, the cable is composed of manganin or constantan. In some cases the cable can be cut into some pieces and each piece is connected at the end points by means of a thick metal strip. Usually they will be copper strips. Each piece of cable has the length of one meter. Generally there will be six pieces of cable and the total length of the cable is six meters. In general, the cable length varies from 4 meters to 10 meters. The greater the length of the cable the better the accuracy of the potentiometer.
The potentiometer consists of a driving circuit consisting of a battery, key and rheostat. It also consists of a galvanometer and a jockey. The end points or terminals of the potentiometer are connected to the points where the potential difference must be measured.