Question

In which of the following cases, the strength of an electromagnet can be increased?

• A. Increasing the current.
• B. Increasing the number of turns.
• C. Using soft iron core of larger cross section.
• D. Changing the direction of current in electromagnet.

Answer 1

Answer: (A), (B), (C)

Using soft iron core of larger cross section.

The strength of an electromagnet depends on:
(1)The number of turns in the coil. If we increase the number of turns in the coil, the strength of electromagnet increases.
(2)The current flowing in the coil. If the current in the coil is increased, the strength of electromagnet increases.
(3)The material of the core. The strength of the magnetic field increases, if we use a soft iron core of larger cross section.

However, changing the direction of current in electromagnet just changes the direction of the magnetic field. Its strength remains unaffected.