Potentiometer

A passive electronic component that can act as a voltage divider is often called as the potentiometer.Its main task is to regulate the current flowing in the circuit.It is basically a variable resistor having three terminals and it allows us to vary the resistance so as to get the desired value of electric current. Among the three terminals the two are the end terminals and the one between them is the terminal called as wiper.The voltage is always measured between the wiper and either of the ends.In a potentiometer the  resistive element (wire made of manganin or constantan)is provided with the voltage source(battery) so that a voltage divider circuit could be designed.The wiper is the moving unit of potentiometer. However the other two ends are fixed.The wiper acts as a variable resistor when it is connected to one of the ends of the potentiometer.

Working principle

The potentiometer works on the principle that drop in the potential over any part of the wire  is proportional to the length of the wire.

Types of potentiometer

Rotary and Linear are the two types of potentiometers.The working principle of both of these is nearly same. But in linear potentiometers the motion of wiper is always linear whereas in rotational potentiometers the motion of wiper is always rotational.Linear potentiometers are used in steering systems, professional mountain bikes, special effects in movies etc.

Rotary potentiometers are used in ticket barriers, marine vehicle systems etc.

Applications of potentiometer

Potentiometer can be used to compare the emf(electro motive force) of two cells.

Potentiometer can be handy in measuring the internal resistance of a battery cell.It is used in medical instruments, television and radio for regulating volume . They are also used as light dimmers in houses.They are used in transducers.Motion control can also be accomplished with the help of potentiometers.