Question

A galvanometer having 30 divisions has a current sensitivity of $20\mu A/div$.It has a resistance of 25 ohm. How will you convert it into an ammeter measuring upto 1 ampere. Find shunt to be used

• A. $0.15\Omega$
• B. $0.015\Omega$
• C. $0.030\Omega$
• D. $0.30\Omega$

Answer 1

The correct option is B $0.015\Omega$

$S=\frac{G}{n-1}=\frac{2.5}{\frac{I}{I_g}-1}=\frac{25}{\frac{I}{600\times {10}^{-6}}-1}=\frac{25}{\frac{10000}{6}-1}=\frac{150}{10000}=0.015\Omega$