Chapter-4|Moving Charges and Magnetism| NCERT 12th Physics:
Conversion of Galvanometer to Voltmeter:
Voltmeter: A device used to measure potential difference in a appliance.
Voltmeter is always connected in parallel with appliance.
Important Concept: The resistance of an ideal voltmeter should be infinity.
Example: A voltmeter whose coil has resistance 10 ohm, gives full scale deflection for 1 mA. How can you convert it into a voltmeter of range 0-2.5 V.