Concept:A galvanometer is converted into a voltmeter by connecting a high value resistor in series with it.
Explanation:A galvanometer alone can measure only very small currents.
To measure the potential difference across a resistor
R, the galvanometer must be made to act as a voltmeter.
Connecting a high value resistor in series with
G limits the current passing through the galvanometer.
This enables the galvanometer to measure larger potential differences safely without being damaged.
Answer:D. high value resistor connected in series with G.