What is the value of shunt resistance required to convert a galvanometer of resistance `100 Omega` into an ammeter of range 1 A ?
Given: Full scale deflection of the galvanometer is 5 mA.

Options

A. `0.5 Omega`
B. `(5)/(9.95) Omega`
C. `0.05 Omega`
D. `(9.95)/(5) Omega`

Answer

B

Explanation

Here,
Resistance of galvanometer, `G=100 Omega`
Full scale deflection current, `I_(g)=5 mA`
`5xx10^(-3)A`

To convert the galvanometer into an ammeter of range 1 A, a shunt resistance of value of S is connected in parallel with it such that,
`(I-I_(g))S=I_(g)G`
`S=(I_(g)G)/(I-I_(g))=(5xx10^(-3)xx100)/(I-5xx10^(-3))=(5xx10^(-1))/(1-0.005)`
`=(0.5)/(0.995)=(5)/(9.95)Omega`