Which one of the following is correct?

1.	The magnetic field lines also represent the lines of force on a moving charged particle at every point.
2.	Magnetic field lines can be entirely confined within the core of a toroid, but not within a straight solenoid.
3.	A bar magnet exerts a torque on itself due to its own field.
4.	Magnetic field arises due to stationary charges.

Which of the following is the correct representation of magnetic field lines?

1. (g), (c)

2. (d), (f)

3. (a), (b)

4. (c), (e)

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:

1. 1/T

2. T

3. 1/T²

4. T²

If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by µ_d, µ_p, and µ_f respectively, then:

1. µ_p = 0 and µ_f ≠ 0

2. µ_d ≠ 0 and µ_p = 0

3. µ_d ≠ 0 and µ_f ≠ 0

4. µ_d = 0 and µ_p ≠ 0

For protecting a magnetic needle, it should be placed:

The correct direction of the magnetic field in the given figures is shown by:

1.		2.
3.		4.

Figure shows two small identical magnetic dipoles a and b of magnetic moments M each, placed at a separation 2d, with their axes perpendicular to each other. The magnetic field at the point P midway between the dipoles is:

1. $\frac{2{\mathrm{\mu }}_0\mathrm{M}}{4{\mathrm{\pi d}}^3}$

2. $\frac{{\mathrm{\mu }}_0\mathrm{M}}{4{\mathrm{\pi d}}^3}$

3. Zero

4. $\frac{\sqrt{5}{\mathrm{\mu }}_0\mathrm{M}}{4{\mathrm{\pi d}}^3}$

At a certain location in Africa, a compass points 12° west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points 60° above the horizontal. The horizontal component of the earth’s field is measured to be 0.16 G. The magnitude of the earth’s field at the location is:

1. 0.16 G

2. 0.48 G

3. 0.32 G

4. 0.30 G

The vertical component of Earth’s magnetic field at a place is equal to the horizontal component. What is the value of the angle of dip at this place?
1. ${30}^{\mathrm{o}}$
2. ${45}^{\mathrm{o}}$
3. ${60}^{\mathrm{o}}$ 
4. ${90}^{\mathrm{o}}$