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

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 \(\left(\theta = \frac{\pi}{n}\right)\)

1. \(\frac{\left(\mu\right)_{o} i}{2 πa} tan \frac{\pi}{n}\)                                               
2. \(\frac{\left(\mu\right)_{0} n i}{2 πa} tan \frac{\pi}{n}\)

3.\(\frac{2}{\pi} \frac{n i}{a} \left(\mu\right)_{0} tan \frac{\pi}{n}\)                                           
4. \(\frac{n i}{2 a} \left(\mu\right)_{0} tan \frac{\pi}{n}\)

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

1. \(\frac{\mu_{0}}{4 \pi} \frac{i}{a} 2 - \frac{\pi}{2} \hat{j}\)             
2. \(\frac{\mu_{0}}{4 \pi} \frac{i}{a}2 + \frac{\pi}{2} \hat{j}\)
3. \(\frac{\mu_{0}}{4 \pi} \frac{i}{a}2 + \frac{\pi}{2} \hat{i}\)             
4. \(\frac{\mu_{0}}{4 \pi} \frac{i}{a} 2 + \frac{\pi}{2} \hat{k}\) 

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 \(B'\text{s}\) direction. What will happen to the wire?

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