Question

Magnets lose their properties if :

• A. A.C. is passed through them
• B. heated strongly
• C. dropped from a height
• D. all of the above

Answer 1

Answer: (A), (B)

The correct options are
A heated strongly
B A.C. is passed through them

When a magnet is treated above 176℉ (80)℃ magnet will quickly loose their magnetic properties. The magnet will become permanently demagnetized if exposed to those temperatures for a certain length of time.

By passing an alternating current the magnetic property can be removed because the alternating current produces a reverse magnetizing field which opposes the object magnetism.