The resistance of a galvanometer is 50 Ω. When 0.01A current flows in it, full scale deflection is obtained in galvanometer, the resistance of shunt connected to convert galvanometer into an ammeter of range 5A, will be
0.1 Ω
0.2 Ω
0.3 Ω
0.4 Ω
A.
0.1 Ω
Galvanometer is a very sensitive instrument therefore it cannot measure heavy currents. In order to convert a Galvanometer into an Ammeter, a very low shunt resistance is connected in parallel to Galvanometer. Value of shunt is so adjusted that most of the current passes through the shunt.
Here :- Ig =0.01A, G=50Ω
If resistance of galvanometer is Rg and it gives full-scale deflection when current Ig is passed through it. Then,
V=IgRg
V=0.01A × 50Ω
Let a shunt of resistance (Rs) is conected in parallel to galvanometer. If total current through the circuit is I
I =5A= Is +Ig
V=IsRs =(I-Ig)Rs
(I-Ig)Rs = IgRg
(5-0.01)Rs= 0.01×50
Rs =0.01Ω
