By error, a student places moving-coil voltmeter V (nearly ideal) in series with the resistance in a circuit in order to read the current, as shown. The voltmeter reading (in V) will be

Question

G1 Physics · Accepted Answer

Treat an ideal voltmeter as open circuit and an ideal ammeter as zero resistance; for galvanometer conversion use the standard series/shunt resistance relations. Substituting the given values gives 12.