Question

The resistance of a galvanometer is $ 25\,\Omega $ , and it requires $ 50\,\mu A $ for full deflection. The value of the shunt resistance required to convert it into an ammeter of 5 A is

• A. $ 2.5\times {{10}^{-4}}\Omega $
• B. $ 1.25\times {{10}^{-3}}\Omega $
• C. $ 0.05\,\Omega $
• D. $ 2.5\,\Omega $

Answer 1

Answer: (A)

$ S=\frac{{{I}_{g}}G}{I-{{I}_{g}}}=\frac{50\times {{10}^{-6}}\times 24}{5-50\times {{10}^{-6}}} $ $ =2.5\times {{10}^{-4}}\,\Omega $