What is the magnetic dipole moment of the given loop?

                 

1.	\({ 5 \over 2} \pi R^2I\)	2.	\(3 \pi R^2I\)
3.	\({ 3 \over 2} \pi R^2I\)	4.	\(5 \pi R^2I\)

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

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.  $\frac{2\mathrm{qB}\left(\mathrm{b} - \mathrm{a}\right)}{\mathrm{m}}$

2.  $\frac{\mathrm{qB}\left(\mathrm{b} + \mathrm{a}\right)}{2\mathrm{m}}$

3.  $\frac{\mathrm{qB}\left(\mathrm{b} - \mathrm{a}\right)}{\mathrm{m}}$

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

A closed-loop (of any shape) carrying current lies in the x-y plane. What happens when a uniform magnetic field B is present in the region such that the loop experiences zero force?

A galvanometer of resistance 240 Ω allows only 4% of the main current after connecting a shunt resistance. What is the value of shunt resistance?

1.  10 $\mathrm{\Omega }$

2.  20 $\mathrm{\Omega }$

3.  8 $\mathrm{\Omega }$

4.  5 $\mathrm{\Omega }$

The dots in the figure depict a magnetic field that is perpendicular to the plane of the paper and emanates from it. The trajectory of a particle in the plane of the paper is depicted by the curve ABC. What exactly is the particle?

A long solenoid has 800 turns per meter length of the solenoid. A current of 1.6 A flows through it. The magnetic induction at the end of the solenoid on its axis is:

1.  $16\times {10}^{-4} \mathrm{T}$

2.  $8\times {10}^{-4} \mathrm{T}$

3.  $32\times {10}^{-4} \mathrm{T}$

4.  $4\times {10}^{-4} \mathrm{T}$

The unit of reduction factor of the tangent galvanometer is 

(1) Ampere

(2) Gauss

(3) Radian

(4) None of these

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