Q.
A moving coil Galvanometer of resistance 100Ω is used as an ammeter using aresistance 0.1Ω. The maximum deflection current in the Galvanometer is 100μA. Find the minimum current in the circuit so that ammeter shows maximum deflection?
We are given with following ammeter
Now, VAB=IgG=(I−Ig)S (100×10−6)100=(I−100×10−6)0.1 I−100×10−6=10−1 I=0.1+100×10−6 =0.1+0.0001=0.1001A=100.1mA
So, circuit current is 100.1mA.