Question

State the principle of working of a galvanometer.

A galvanometer of resistance G is converted into a voltmeter to measure up to V volts by connecting a resistance R1, in series with the coil. If a resistance R2, is connected in series with it, then it can measure up to V/2 volts. Find the resistance, in terms of R1 and R2, required to be connected to convert it into a voltmeter that can read up to 2 V Also find the resistance G of the galvanometer in terms of R1, and R2.

Answer 1

Working principle : A current carrying coil experience torque when placed in a magnetic field which tends to rotate the coil and produces an angular deflection.

Let R3, be the resistance required for conversion into voltmeter o{ range 2 V.