A particle with charge q, moving with a momentum p, enters a uniform magnetic field normally. The magnetic field has magnitude B and is confined to a region of width d, where $d<\frac{p}{Bq}$. The particle is deflected by an angle $\theta$ in crossing the field, then:

  

1.	\(\sin \theta={Bqd \over p}\)	2.	\(\sin \theta={p \over Bqd}\)
3.	\(\sin \theta={Bp \over qd}\)	4.	\(\sin \theta={pd \over Bq}\)

The same current i = 2A is flowing in a wireframe as shown in the figure. The frame is a combination of two equilateral triangles ACD and CDE of side 1m. It is placed in uniform magnetic field B = 4T acting perpendicular to the plane of the frame. The magnitude of the magnetic force acting on the frame is:

1. 24 N                                        
2. Zero
3. 16 N                                         
4. 8 N

In the given figure net magnetic field at O will be  i

(a) $\frac{{\mu }_{0}i}{3\mathrm{\pi a}}\sqrt{4-{\mathrm{\pi }}^2}$                                 (b) $\frac{{\mu }_{0}i}{3\mathrm{\pi a}}\sqrt{4+{\mathrm{\pi }}^2}$

(c) $\frac{2{\mu }_{0}i}{3\mathrm{\pi a}}\sqrt{4+{\mathrm{\pi }}^2}$                                  (d) $\frac{2{\mu }_{0}i}{3\mathrm{\pi a}}\sqrt{\left(4-{\mathrm{\pi }}^2\right)}$

In the following figure a wire bent in the form of a regular polygon of n sides is inscribed in a circle of radius a. Net magnetic field at centre will be $\left(\theta =\frac{\pi }{n}\right)$

(a) $\frac{{\mu }_{o}i}{2\mathrm{\pi a}}\tan \frac{\mathrm{\pi }}{n}$                                                (b) $\frac{{\mu }_{0}ni}{2\mathrm{\pi a}}\tan \frac{\mathrm{\pi }}{n}$

(c)$\frac{2}{\mathrm{\pi }}\frac{ni}{a}{\mu }_0\tan \frac{\mathrm{\pi }}{n}$                                             (d) $\frac{ni}{2a}{\mu }_0\tan \frac{\mathrm{\pi }}{n}$

The unit vectors $\hat{i}, \hat{j} and \hat{k}$ are as shown below. What will be the magnetic field at O in the following figure?

(a) $\frac{{\mu }_0}{4\mathrm{\pi }}\frac{i}{a}\left(2-\frac{\mathrm{\pi }}{2}\right)\hat{j}$             (b) $\frac{{\mu }_0}{4\mathrm{\pi }}\frac{i}{a}\left(2+\frac{\mathrm{\pi }}{2}\right)\hat{j}$

(c) $\frac{{\mu }_0}{4\mathrm{\pi }}\frac{i}{a}\left(2+\frac{\mathrm{\pi }}{2}\right)\hat{i}$              (d) $\frac{{\mu }_0}{4\mathrm{\pi }}\frac{i}{a}\left(2+\frac{\mathrm{\pi }}{2}\right)\hat{k}$ 

A particle of charge q and mass m moves in a circular orbit of radius r with angular speed ω. The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on

(1) ω and q

(2) ω, q and m

(3) q and m                     

(4) ω and m

A current I is carried by an elastic circular wire of length L. It is placed in a uniform magnetic field B (out of paper) with its plane perpendicular to B's direction. What will happen to the wire?

          \(F ~\)

Wires 1 and 2 carrying currents $i_1$ and $i_2$ respectively are inclined at an angle $\theta$ to each other. What is the force on a small element dl of wire 2 at a distance of r from wire 1 (as shown in figure) due to the magnetic field of wire 1

(a) $\frac{{\mu }_0}{2\mathrm{\pi r}}{i}_1{i}_{2}dl \tan \theta$                              (b) $\frac{{\mu }_0}{2\mathrm{\pi r}}{i}_1{i}_{2}dl \sin \theta$

(c) $\frac{{\mu }_0}{2\mathrm{\pi r}}{i}_1{i}_{2}dl \cos \theta$                               (d) $\frac{{\mu }_0}{4\mathrm{\pi r}}{i}_1{i}_{2}dl \sin \theta$

A conducting loop carrying a current I is placed in a uniform magnetic field pointing into the plane of the paper as shown. The loop will have a tendency to

(1) Contract                                       

(2) Expand 

(3) Move towards +ve x -axis               

(4) Move towards -ve x -axis

A metallic block carrying current I is subjected to a uniform magnetic induction $\stackrel{\rightharpoondown }{B}$ as shown in the figure. The moving charges experience a force  $\stackrel{\rightharpoondown }{F}$ given by ........... which results in the lowering of the potential of the face ........ Assume the speed of the carriers to be v

(1) $eVB\hat{k}$ , ABCD                               

(2) $eVB\hat{k}$ , EFGH

(3) $-eVB\hat{k}$ , ABCD                             

(4) $-eVB\hat{k}$ , EFGH