Question

To measure the magnetic moment of a bar magnet, one may use.

• A. a tangent galvanometer.
• B. a deflection galvanometer if the earth's horizontal field is known.
• C. an oscillation magnetometer if the earth's horizontal field is known.
• D. both deflection and oscillation magnetometer if the earth's horizontal field is not known.

Answer 1

Answer: (B), (C), (D)

The correct options are
B an oscillation magnetometer if the earth's horizontal field is known.
C both deflection and oscillation magnetometer if the earth's horizontal field is not known.
D a deflection galvanometer if the earth's horizontal field is known.

To measure the magnetic moment of a bar magnet,
a deflection galvanometer is used if the earth's horizontal field is known.
An oscillation magnetometer can be used if the earth's horizontal field is known.
Both deflection and oscillation magnetometer can be used if the earth's horizontal field is not known since there are two variables.