Question

A galvanometer with a full scale current of 10 mA has a resistance of $1000\Omega$. The multiplying power (the ratio of measured current to galvanometer current) of $100\Omega$ shunt with this galvanometer is

• A. 110
• B. 100
• C. 11
• D. 10

Answer 1

The correct option is C 11


Full scale current of galvanometer,
$I_m=10mA$

Resistance of meter
$R_m=1000\Omega$

Resistance of shunt
$R_{sh}=100\Omega$

$I_m=\frac{I{R}_{sh}}{R_{sh}+R_m}$

Multiplying power
$=\frac{I}{I_m}=\frac{R_{sh}+R_m}{R_m}$

$=\frac{100+1000}{100}=11$