A galvanometer has a coil of resistance 200Ω with a full scale deflection at 20 μA. The value of resistance to be added to use it as an ammeter of range (0-20) mA is [2024]
0.40Ω
0.20Ω
0.50Ω
0.10Ω
(B) G=200 Ω and ig=20 μA
i=ig(GS+1)
⇒20×10-3=20×10-6(200S+1)
⇒200S=999⇒S≈0.2Ω
