Question

In a galvanometer 5% of the total current in the circuit passes through it. If resistance of the galvanometer is G, the, resistance of the shunted galvanometer is

• A. $19G$
• B. $\frac{G}{19}$
• C. $20G$
• D. $\frac{G}{20}$

Answer 1

The correct option is B $\frac{G}{19}$

Given : 5% of total current passes through galvanometer of resistance G.

Solution:

Let us assume that total current is 100i

Galvanomter and shunt resistance are connected in parellal so they have same voltage V

Current through the galvanometer is 5i as 5% total current passes through it.

using ohm's law we get V=5iG eq-1

Current through Shunt resistance is 95i

Using ohm's law we get V=95iR eq-2

Solving eq-1 and eq-2 we get $R=\frac{G}{19}$

The correct opt : B