Question

A galvanometer having a resistance of 8 Ω is shunted by a wire of resistance 2 Ω. If the total current is 1 amp, the part of it passing through the shunt will be

• A. 0.25 amp
• B. 0.8 amp
• C. 0.2 amp
• D. 0.5 amp

Answer 1

Answer: (B)

0.8 amp

Answer 2

Fraction of current passing through the galvanometer

$\frac{i_{g}}{i} = \frac{S}{S + G}$ or $\frac{i_{g}}{i} = \frac{2}{2 + 8} = 0.2$

So fraction of current passing through the shunt

$\frac{i_{s}}{i} = 1 - \frac{i_{g}}{i} = 1 - 0.2 = 0.8amp$