Question

A moving coil galvanometer of resistance $100 \Omega$ is used as an ammeter using a resistance $0.1 \Omega$. The maximum deflection current in the galvanometer is $100 \mu A$. Find the current in the circuit, so that the ammeter shows maximum deflection.

• A. 100.0 mA
• B. 1000.0 mA
• C. 10.01 mA
• D. 1.01 mA

Answer 1

Answer: (A)

100.0 mA

Answer 2

$V_{ab} = i_g.G = (i - i_g) S \, \, \, \, \, \, \Rightarrow \, \therefore \, i = \bigg( 1 + \frac{G}{S} \bigg) i_g$
Substituting the values, we get
$\, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, i = 100.1 mA$
$\therefore$Correct answer is (a).