If the planes of two identical concentric coils are perpendicular and the magnetic moment of each coil is \(M,\) then the resultant magnetic moment of the two-coil system will be:

1.	\(M\)	2.	\(\sqrt{2} M\)
3.	\(3 M\)	4.	\(2 M\)

Which of the following graphs correctly represents the variation of magnetic field induction with distance due to a thin wire carrying current?

1.		2.
3.		4.

When an electron enters perpendicularly in a magnetic field with velocity v, time period of its revolution is T. If it enters in the same magnetic field with a velocity 2v, then its time period will be:

1.  2T

2.  4T

3.  $\frac{\mathrm{T}}{2}$

4.   T

What is the magnetic dipole moment of the given loop?

The figure shows a particle of charge q and mass m moving with velocity v along the x-axis enters a region of the uniform magnetic field. The minimum value of v so that the charge q is deflected by an angle $30°$ is

1.  $\frac{2\mathrm{qB}\left(\mathrm{b}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>\mathrm{a}\right)}{\mathrm{m}}<mspace\; width="1em"></mspace>$

2.  $\frac{\mathrm{qB}\left(\mathrm{b}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>\mathrm{a}\right)}{2\mathrm{m}}<mspace\; width="1em"></mspace>$

3.  $\frac{\mathrm{qB}\left(\mathrm{b}<mspace\; width="1em"></mspace>-<mspace\; width="1em"></mspace>\mathrm{a}\right)}{\mathrm{m}}<mspace\; width="1em"></mspace>$

4.  $\frac{\mathrm{qBb}}{2\mathrm{m}}$

An electron is traveling along the x-direction. It encounters a magnetic field in the y-direction. Its subsequent motion will be:

1.  Straight-line along the x-direction

2.  A circle in the xz-plane

3.  A circle in the yz-plane

4.  A circle in the xy-plane

The magnetic field at center due to the orbital motion of the electron in the hydrogen atom is :

1.  12.5 tesla

2.  5 tesla

3.  24 tesla

4.  1 tesla

A positively charged particle descends vertically. In which direction will the horizontal component of the earth's magnetic field deflect?

1. east

2. west

3. north

4. south