Question

A milli-ammeter of range 10mA has a coil of resistance 2$\Omega$ . To use it as an ammeter of range 1A, the required shunt must have a resistance of

• A. 1/101 Ω
• B. 1/100 Ω
• C. 2/99 Ω
• D. 1/99 Ω

Answer 1

The correct option is C

2/99 Ω

$i_{g}G=(i-i_g)s\Rightarrow S=\frac{i_{g}G}{i-i_g}=\frac{0.01\times 2}{1-0.01}=\frac{0.02}{0.99}$