Question

Name the instrument used to control current in an electric circuit.

Answer 1

Rheostat:

1. A rheostat is defined as a kind of variable resistor that is used for controlling the flow of electric current just by increasing or decreasing the resistance.
2. It is a resistor that is used in some of the applications that may require the controlling or adjustment of current or varying the resistance in an electric circuit.
3. It may be used to adjust generator characteristics also, very dim lights, and start or control the speed variation of motors.
4. A thin resistive wire is wound around an insulated core of ceramic and a wiper slides over the core windings.
5. We use the symbol of rheostat as the same as that normal resistor symbol but includes an arrow on it.
6. This arrow is an indication of the movable wiper or variable resistance.
7. The main difference between rheostat and resistance is that the rheostat is an electrical resistor with two terminals while the resistance is a parameter that can be varied continuously by moving the knob.

Thus, the rheostat is the instrument, which we can use to control the current in an electric circuit.