Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius and respectively. The ratio of mass of X to that of Y is :
1. 2.
3. 4.
Two thin long parallel wires separated by a distance b are carrying a current i amp each. The magnitude of the force per unit length exerted by one wire on the other is
1.
2.
3.
4.
A small coil of N turns has an effective area A and carries a current I. It is suspended in a horizontal magnetic field such that its plane is perpendicular to . The work done in rotating it by about the vertical axis is
1. 2.
3. 4.
Which among the following options needs to be decreased to increase the sensitivity of a moving coil galvanometer?
1. | the number of turns in the coil. | 2. | the area of the coil. |
3. | the magnetic field. | 4. | the couple per unit twist of the suspension. |
An electron, moving in a uniform magnetic field of induction of intensity has its radius directly proportional to :
1. Its charge
2. Magnetic field
3. Speed
4. None of these
A particle of charge \(q\) and mass \(m\) is moving along the \(x\text-\)axis with a velocity of \(v\) and enters a region of electric field \(E\) and magnetic field \(\mathrm B\) as shown in the figure below. For which figure is the net force on the charge zero?
1. | 2. | ||
3. | 4. |
A long straight wire along the z-axis carries a current I in the negative z-direction. The magnetic field vector at a point having coordinates (x, y) in the z = 0 plane is :
1.
2.
3.
4.
Figure shows a square loop ABCD with edge length a. The resistance of the wire ABC is r
and that of ADC is 2r. The value of magnetic field at the centre of the loop assuming
uniform wire is
1.
2.
3.
4.
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 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. \(\frac{\mu_{0}}{4 \pi} \frac{i}{a} 2 + \frac{\pi}{2} \hat{k}\)