Tag: properties of a magnetic field

Methods by which a magnet can be demagnetized can be given as mentioned below: 
$(1)$ Heating a magnet strongly
$(2)$ Hammering the magnet several times or repeated hammering
$(3)$ By passing an alternating current through the magnet
Hence, the correct options $(A)$ and $(B)$.

The magnet can loose it property heating, by hammering and by using demagnetizing field we can demagnetize a magnet,On dropping it from certain height.

Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone.

A magnet can be easily turned into a permanent magnet by excessive heating.

Magnetite is a naturally occurring iron ore that exhibits strong magnetic properties, historically known as lodestone.

Casting of a magnetic material, pressing and sintering of magnetic material and extruding of magnetic material are the processes used for making permanent magnets.

Iron, cobalt and steel are ferromagnetic materials which can be used to make magnet but ebonite cannot be used to make magnets.

Among the following options, magnetite is the only natural magnet.

The phenomenon of converting a substance into a magnet by flowing an electric current through a coil around it is known as electromagnetism and the magnet so formed is known as electromagnet.