Conversion of Galvanometer to Voltmeter – Rankers Physics

Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ): Practice Problem & Solution

A galvanometer coil has a resistance of \(12\ \Omega\) and the meter show full scale deflection for a current of \(1\text{ mA}\). The resistance required to be added to convert the galvanometer into a voltmeter of range \(0\) to \(10\text{ V}\) will be
\(9988\ \Omega\) in parallel
\(9988\ \Omega\) in series
\(10000\ \Omega\) in parallel
\(10000\ \Omega\) in series

Solution Explained:

To solve this problem, we apply the core principles of Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ). Understanding the underlying formula is key to arriving at the correct answer below:

To convert a galvanometer into a voltmeter, a high resistance \(R\) is connected in series: \(V = I_g(G + R) \implies 10 = 10^{-3}(12 + R) \implies R = 9988\ \Omega\).

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