The sensitivity of a galvanometer is 60 divisions per ampere. When a shunt is used its sensitivity becomes 10 divisions per ampere. If the galvanometer is of 20 Ω resistance, the value of the shunt is :

Question

The sensitivity of a galvanometer is 60 divisions per ampere. When a shunt is used its sensitivity becomes 10 divisions per ampere. If the galvanometer is of 20 Ω resistance, the value of the shunt is : (A) 2 Ω (B) 4 Ω (C) 5 Ω (D) 8 Ω

Tardigrade Admin · Accepted Answer

Let the number of divisions on the scale be n. Then Ig = (n/60) and I = (n/10) , Also Ig × 20 = ( I - Ig)S This gives S = 4.

Q. The sensitivity of a galvanometer is 60 divisions per ampere. When a shunt is used its sensitivity becomes 10 divisions per ampere. If the galvanometer is of $20 Ω$ resistance, the value of the shunt is :

$2 Ω$

$4 Ω$

$5 Ω$

$8 Ω$

Let the number of divisions on the scale be $n$ . Then $I_{g} = \frac{n}{60}$ and $I = \frac{n}{10}$ ,
Also $I_{g} \times 20 = (I - I_{g}) S$
This gives $S$ = 4.

Q. The sensitivity of a galvanometer is 60 divisions per ampere. When a shunt is used its sensitivity becomes 10 divisions per ampere. If the galvanometer is of 20Ω resistance, the value of the shunt is :

2Ω

4Ω

5Ω

8Ω