Magnetism and M...

The materials suitable for making electromagnets should have

Curie temperature is the temperature above which:

Relative permittivity and permeability of a material are ε_r and μ_r respectively. Which of the following values of these quantities are allowed for a diamagnetic material?

Needles N₁, N₂ and N₃ are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet, when brought close to them, will

If a diamagnetic substance is brought near north or south pole of a bar magnet, it is

A bar magnet of magnetic moment M is cut into two parts of equal lengths. The magnetic moment and pole strength of either part is:

A magnet of moment 4Am$$^{2}$$ is kept suspended in a magnetic field of induction $$5\times 10^{-5}T$$. The workdone in rotating it through 180$$^{0}$$ is

To explain ferromagnetism, we use

A bar magnet of magnetic moment $$2Am^{2}$$ is free  to rotate about a vertical axis passing through its center. The magnet is released from rest from east - west position. Then the KE of the magnet as it takes N-S position is
$$(B_{H}=25\mu T)$$

In the hystersis cycle, the value of H needed to make the intensity of magnetisation zero is called

The core of electromagnet is made of soft iron, because
a) susceptibility of soft iron is very high
b) coercivity of soft iron is very low

Maximum P.E. of magnet of moment M situated in a magnetic field of induction B, is

A short bar magnet placed with its axis at $$30^{o}$$ with a uniform external magnetic field of $$0.16\ T$$ experiences a torque of magnitude $$0.032 Nm$$  If the bar magnet is free to rotate, its potential energies when it is in stable and unstable equilibrium are respectively

The value of susceptibility for super conductor is

The work required to rotate a magnetic needle by 60$$^{0}$$ from equilibrium position in a uniform magnetic field is W. The torque required to hold it in that position is

A coil of area $$A$$, turns $$N$$ and carrying current $$i$$ is placed with its face parallel to the lines of magnetic induction $$B$$. The work done in rotating the coil through an angle of $$180^{0}$$ is