Given, Resistance of galvanometer, G=100Ω Current, ig=1mA A galvanometer can be converted into voltmeter by connecting a large resistance R in series with it. Total resistance of the combination =G+R According to Ohm's law, V=ig(G+R) ∴10=1×10−3(100+R0) ⇒10000−100=9900Ω=R0 ⇒R0=9.9kΩ