Question

The strength of the magnetic field produced by a solenoid can be altered by changing the ________.

• A. Direction of current
• B. Magnitude of current
• C. Number of turns in the coil
• D. Both (B) and (c)

Answer 1

The correct option is D

Both (B) and (c)

Explanation for the correct options

D: Both (B) and (c)

B: Magnitude of the current

1. A solenoid is an artificial magnet whose magnetism is due to the current flowing through its coil.
2. The strength of the magnetic field produced by a solenoid is directly proportional to the current flowing through its coil.
3. More the electric current, the more is the strength of the magnetic field produced and vice versa.
4. Hence, by changing the electric current flowing through the coil of the solenoid, the strength of its magnetic field can be altered.

C: Number of turns in the coil

1. The strength of the magnetic field produced by a solenoid is directly proportional to the number of turns in the coil of the solenoid.
2. More the number of turns of the coil, the more is the strength of the magnetic field and vice versa.
3. Hence, by altering the number of turns, the strength of the magnetic field can be altered.

Explanation for the incorrect option

A: Direction of current

1. Changing the direction of the electric current changes the polarity of the solenoid and not the strength of the magnetic field produced by it.

Hence, option (D) is correct.