Question

You are given an iron strip. How will you convert it into a permanent magnet?

• A. By putting into hot water
• B. By placing a magnet near it for few hours
• C. By rubbing it with a magnet for few minutes
• D. It can't be converted

Answer 1

The correct option is C

By rubbing it with a magnet for few minutes

When the iron strip is dropped into hot water, it becomes hot. However, it does not attain magnetic properties.
When a magnet is placed near the strip for a few hours, it gets attracted to the magnet and temporarily attains magnetic properties. However, when the magnet is taken away, it loses the magnetic properties.
When a bar magnet is rubbed over the strip in single or double touch method i.e. dragging the iron strip on the magnet in a particular manner repeatedly, then the strip attains magnetic properties which it retains for a long period of time.