Question

A galvanometer has a resistance of 96 Ω  and it is desired to pass 4% of the total current through it. The value of shunt resistance is ____?

Answer 1

Correct Answer: 4

Explanation:
It is given that,
The resistance of the galvanometer, Rg = 96Ω4% of the total current is passed through the galvanometer, i.e. Ig = 0.04
We have to find the value of shunt resistance.
Let Rs be the shunt resistance.
The shunt resistance is given by,
$R_s=\frac{I_g{R}_g}{I-I_g}$$\Rightarrow R_s=\frac{0.04I\times 96\mathrm{\Omega }}{I-0.04I}$$\Rightarrow R_s=\frac{0.04I\times 96\mathrm{\Omega }}{0.96I}$$\Rightarrow R_s=4\mathrm{\Omega }$
Hence, the correct answer is 4.

Answer 2

Ans. An electromechanical device known as a galvanometer is used to measure and detect the electric current flowing through a circuit. By creating a rotatory deflection of the pointer in response to the electric current flowing through a coil set in a uniform and continuous magnetic field, a galvanometer essentially functions like an actuator. It is a sensitive instrument that can detect even very small currents, on the order of a few microamperes.

Principle of a galvanometer's operation - When a current-carrying coil is exposed to an external magnetic field, magnetic torque results. The amount of current flowing through the coil directly relates to the angle by which the coil is deflected as a result of the magnetic force.

Only little currents may be detected by a galvanometer. Thus, it is transformed into an ammeter to measure enormous quantities of current. Low resistance can be connected in parallel with the galvanometer to accomplish this