Temporary magnets retain magnetism only for a short period of time.

Permanent magnets retain magnetism only for a short time.

Magnets that retain magnetism for a very long period of time

Temporary and permanent magnets

Assertion: Substances which at room temperature retain their ferromagnetic property for a long period of time are called permanent magnets. Reason: permanent magnet can be made by placing a ferramagnetic rod in a solenoid and passing current through it.

The perio of oscillation of a magnet in vibration magnetometer is 2 sec. The period of oscillation of a magnet whosr magnetic moment is four times that of the first magnet is

Two identical short bar magnets of magnetic moment M each are placed at distance r apart in end-on position, then magnetic force between both is

In tan A position two short bar magnets of magnetic moments in the ratio of 1 : sqrt3 aer placed at the same distnace respectively. If the definection produced for the first magnet be 30^(@), then what will be defication for the second magnet ?

Magnetic keepers help to retain magnetism.

Which of the following retains magnetism for a long time?

Time period of a bar magnet oscillating in earth's magnetic field is T. Its magnetic moment is M. Now, a bar magnet of magnetic moment 2M is brought near it. The new time period will be