Question

Dev was asked to identify a soft iron placed in a basket with 9 other magnets of the same shape and size. Which is the easiest way of identifying the iron piece at the earliest?

• A. By suspending the magnets one at a time.
• B. By conducting repulsion test using any two magnets at a time.
• C. By heating all the magnets together.
• D. By dropping all the magnets into the water.

Answer 1

The correct option is B By conducting repulsion test using any two magnets at a time.

• All the magnets in the basket when suspended, will align in north-south direction. This will not help in identifying the soft iron.
• Repulsion is the surest test for magnetism. It is the surest test because any substance made of iron, nickel, cobalt will also have an attraction but won't have repulsion. Dev can conduct the repulsion test by taking two magnets.
• Heating will demagnetize all the magnets wihich will not help in this case.
• Dropping all the magnets in water will make no change in the magnetic properties.