AIIMS Physics Magnetism And Matter Class 12 Questions

Find force per unit length at P.

Find magnetic field at centre P if length of side of square loop is 20 cm.

Two circular loops having same radius [R = 10 cm] and same current \( \frac{7}{2} \) A are placed along same axis as shown. If distance between their centre is 10 cm, find net magnetic field at point P.

Force on current carrying loop (Radius = R) in uniform magnetic (B) field which is at an angle 30° with the normal will be :-

Assertion : The kinetic energy does not change when a particle moves in uniform magnetic field. Reason : The velocity of the particle is not affected by magnetic field.

Assertion: Ferromagnetic compound is more attracted in magnetic field. Reason: Because all electron are alligned in same direction.

MnO is :

If the magnetizing field on a ferromagnetic material is increased, its permeability

The variation of magnetic susceptibility with the temperature of a ferromagnetic material can be plotted as

A solenoid of length 0.6 m has a radius of 2 cm and is made up of 600 turns. If it carries a current of 4 Å, then the magnitude of the magnetic field inside the solenoid.

Assertion: The magnetism of the magnet is due to the spin motion of electron. Reason: The dipole moment of electron is smaller than that due to orbit motion around nucleus.

The angle of dip at a certain place where the horizontal and vertical components of the earth’s magnetic field are equal is

Assertion: In water, value of magnetic field decreases. Reason: Water is diamagnetic substance.

Assertion: Magnetic field is useful in producing parallel beam of charged particle. Reason: Magnetic field inhibits the motion of charged particle moving across it.

Assertion: Magnetic field lines are continuous and closed. Reason: Magnetic monopole does not exist.

Assertion (A) Above Curie temperature, a ferromagnetic material becomes paramagnetic. Reason (R) When a magnetic material is heated to very high temperature, it loses its magnetic properties.

Assertion: A planar circular loop of area A and carrying current I is equivalent to magnetic dipole of dipole moment M = IA. Reason: At large distances, magnetic field of circular loop and magnetic dipole is same.

Assertion: A superconductor is a perfect diamagnetic substance. Reason: A superconductor is a perfect conductor.

Which of the following substances magnetic susceptibility χm is negative?

When orientation of dipoles parallel and antiparallel to magnetic field is distributed unequally, then the material is

Assertion : Magnetic field lines are continuous and closed. Reason : Magnetic monopole does not exist.

Assertion : Magnetic force between two short magnets, when they are co-axial follows inverse square law of distance. Reason : The magnetic forces between two poles do not follow inverse square law of distance.

Which of the following is true regarding diamagnetic substances (symbols have their usual meaning)

Assertion: The magnetic poles of earth do not coincide with the geographic poles. Reason: The discrepancy between the orientation of a compass and true north-south direction is known as magnetic declination.

Assertion : Magnetic susceptibility is a pure number. Reason : The value of magnetic susceptibility for vacuum is one.

The magnetic susceptibility of an ideal diamagnetic substance is

Assertion : A current continues to follow in superconducting coil even after switch is off. Reason : Superconducting coils show Meissner effect.

Assertion : Ferro magnetic substances become paramagnetic above Curie temp. Reason : Domains are destroyed at high temp.

The magnetic moment has dimensions of

Assertion : Diamagnetic materials can exhibit magnetism. Reason : Diamagnetic materials have permanent magnetic dipole moment.

The Magnetic Resonance Imaging (MRI) is based on the phenomenon of

Liquid oxygen remains suspended between two pole faces of a magnet because it is

The magnetic moment of a current (I) carrying circular coil of radius (r) and number of turns (n) varies as

Assertion : The true geographic north direction is found by using a compass needle. Reason : The magnetic meridian of the earth is along the axis of rotation of the earth.

The earth's magnetic field at a given point is 0.5 × 10⁻⁵ Wb/m². This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius 5.0 cm. The current required to be flown in the loop is nearly

A frog can be levitated in a magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as

Assertion : In high latitudes one sees colourful curtains of light hanging down from high altitudes. Reason : The high energy charged particles from the sun are deflected to polar regions by the magnetic field of the earth.

Assertion : We cannot think of a magnetic field configuration with three poles. Reason : A bar magnet does exert a torque on itself due to its own field.

Force between two identical bar magnets whose centres are r metre apart is 4.8 N when their axes are in the same line. If separation is increased to 2r, the force between them is reduced to