Correct option is A
An induction meter works on the principle of electromagnetic induction, which requires an alternating current (AC) supply to produce a changing magnetic field. It CANNOT be used on DC circuits because there is no changing magnetic flux in DC systems, which is essential for its operation.
Mercury Motor meter – Can work on DC circuits as it uses mercury as a conductor in motorized systems.
Voltmeter – Can measure voltage in both AC and DC circuits.
Commutator motor meter – Specifically designed to work on DC circuits.
