## MCQ (Single Correct Answer)

A big circular coil of 1000 turns and average radius 10 m is rotating about its horizontal diameter at 2 rad s$$-$$1. If the vertical component of ear...

A thick current carrying cable of radius 'R' carries current 'I' uniformly distributed across its cross section. The variation of magnetic field B(r) ...

In the product$$\overrightarrow F = q\left( {\overrightarrow v \times \overrightarrow B } \right)$$$$ = q\overrightarrow v \times \left( {B\widehat...

A uniform conducting wire of length 12a and resistance 'R' is wound up as a current carrying coil in the shape of ,(i) an equilateral tringle of side ...

An iron rod of susceptibility 599 is subjected to a magnetizing field of 1200 A m-1. The permeability of the material of the rod is :$$\left( {{\mu _0...

At a point A on the earth’s surface the angle of dip, $$\delta $$ = + 25o. At a point B on the earth's surface the angle of dip, $$\delta $$ = – 25o. ...

A thin diamagnetic rod is placed vertically
between the poles of an electromagnet. When
the current in the electromagnet is switched
on, then the diam...

If $$\theta $$1 and $$\theta $$2 be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of d...

A 250-turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of 85 $$\mu $$A and subjected to a magnetic field of strength 0.85 T....

A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 6...

The magnetic susceptibility is negative for

A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 weber/...

Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $$\overrightarrow m .$$ Whic...

A bar magnet of magnetic moment M is placed at right angles to a magnetic induction B. If a force F is experienced by each pole of the magnet, the len...

A current loop in a magnetic field

A bar magnet of length $$'l'$$ and magnetic dipole moment 'M' is bent in the form of an arc as shown in figure. The new magnetic dipole moment will be...

A magnetic needle suspended parallel to a magnetic field requires $$\sqrt 3 J$$ of work to turn it through 60o. The torque needed to maintain the need...

A compass needle which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It

A short bar magnet of magnetic moment 0.4 J T$$-$$1 is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the pote...

There are four light-weight-rod samples A, B, C, D separately suspended by threads. A bar magnet is slowly brought near each sample and the following ...

The magnetic moment of a diamagnetic action is

Two identical bar magnets are fixed with their centers at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magne...

Electromagnets are made of soft iron because soft iron has

A vibration magnetometer placed in magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2 sec in earth's ...

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

A bar magnet having a magnetic moment of 2 $$ \times $$ 104 J T$$-$$1 is free to rotate in a horizontal plane. A horizontal magnetic field B = 6 $$ \t...

Curie temperature above which

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment $$\mu $$ is given by

Curie temperature above which

A coil in the shape of an equilateral triangle of side $$l$$ is suspended between the pole pieces of a permanent magnet such that $$\overrightarrow B ...

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by $$\mu $$d, $$\mu $$p...

A diamagnetic material in a magnetic field moves

According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature $$T$$ is proportional to

A bar magnet is oscillating in the Earth's magnetic field with a period T. What happens to its period and motion if its mass is quadrupled?

Two bar magnets having same geometry with magnetic moments M and 2M, are firstly placed in such a way that their similar poles are same side then its ...

Among which the magnetic susceptibility does not depened on the temperature ?

Tangent galvanometer is used to measure