Question

Which of the following is true regarding solenoids?

(A) strength of the magnetic field is independent of the material on which the coil is wound.

(B) when the coil is wound around a soft iron core, it behaves like a temporary magnet.

• A. Only A
• B. Only B
• C. Both A and B
• D. None of the above

Answer 1

The correct option is B

Only B

Part A:

1. According to the property of the magnetic field set up in solenoid: The strength of the magnetic field also depends on the nature of the material on which the coil is wound.
2. The magnetic field is maximum when the coil is wound around a soft iron core.

Part B:

1. According to the property of the magnetic field set up in a solenoid, the magnetic field in a solenoid exists as long as there is an electric current in the solenoid.
2. Hence, the magnetic field in the solenoid is a temporary field.
3. Thus, a solenoid behaves like a temporary magnet.

Therefore, when the coil is wound around a soft iron core magnetic field strength is maximum, and the solenoid behaves like a temporary magnet depending on the presence of current.

The correct option is option B.