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

$\begin {array} {1 1} (A)\;100.1 mA & \quad (B)\;1000.1mA \\ (C)\;10.01mA & \quad (dD\;1.01mA \end {array}$

The student is expected to know the working of an ammeter.
$i_gR_g = (i – i_g)R_s$
$i = (1 + \large\frac{R_g}{R_s})$ $i_g$
On substituting the values, one gets $i = 100.1mA.$
Ans : (A)
edited Mar 14, 2014