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 $100\mu \text{A}$. Find the minimum current in the circuit, so that the ammeter shows maximum deflection

• A. $100.1\text{mA}$
• B. $1000.1\text{mA}$
• C. $10.01\text{mA}$
• D. $1.01\text{mA}$

Answer 1

The correct option is A $100.1\text{mA}$


$V_{ab}=i_{g}G=(i-i_g)S$
$\therefore i=(1+\frac{G}{S})i_g$

Substituting the values, we get
$i=(1+\frac{100}{0.1})\times 100\times {10}^{-6}$
or $i=100.1\text{mA}$