The Magnetic field of a magnetized iron bar when strongly heated

Question

Question

This question was previously asked in

IPRC (ISRO) Technician B (Electronics) 2016 Official Paper (Held on 28 Aug 2016)

Answer 1

The Magnetic field of a magnetized iron bar when strongly heated becomes weaker.

Additional Information

As the temperature increases, at a certain point called the Curie temperature, a magnet will lose its strength completely.
Not only will a material lose its magnetism, but it will also no longer be attracted to magnets.
Nickel has a Curie temperature of 358 Celsius (676 Fahrenheit); iron's is 770 C (1418 F).
Once the metal cools, its ability to attract magnets returns, though its permanent magnetism becomes weak.
In general, heat is the factor that has the most effect on permanent magnets.