Question

Permanent magnets can be made using hard magnetic materials Which of the following is not the correct method to make permanent magnets? (a) Using a bar magnet to stroke a steel bar (b) Using two bar magnets to stroke a steel bar (c) Placing a steel bar in a solenoid that connects to a DC supply (d) Placing a steel bar in a solenoid that connects to an AC supply, then slowly withdrawing the steel bar away from the solenoid in West-East direction

Answer 1

Answer:

option (d) is correct

hope it helps you

Answer 2

Option D is the answer

Explanation:

A permanent magnet cannot be made by placing a steel bar in a solenoid that connects to an AC supply, then slowly withdrawing the steel bar away from the solenoid in West-East direction.

But permanent magnets can be made using any of the following methods:  

Using a bar magnet to stroke a steel bar

Using two bar magnets to stroke a steel bar

Placing a steel bar in a solenoid that connects to a DC supply

Hence Option D is the answer.