A neutral point is obtained at the centre of a vertical circular coil carrying current. The angle between the plane of the coil and the magnetic meridian is :
1. 0 2. 45°
3. 60° 4. 90°
If the current is flowing in the south direction along a power line, then what will be the direction of the magnetic field above the power line (neglecting the earth's field)?
1. | South | 2. | East |
3. | North | 4. | West |
An electron and a proton with equal momentum enter perpendicularly into a uniform magnetic field, then :
1. The path of proton shall be more curved than that of electron
2. The path of proton shall be less curved than that of electron
3. Both are equally curved
4. Path of both will be a straight line
Two particles A and B of masses and respectively and having the same type of charge are moving in a plane. A uniform magnetic field exists perpendicular to this plane. The speeds of the particles are and respectively, and the trajectories are as shown in the figure. Then
1.
2.
3.
4.
An electric current passes through a long straight wire. At a distance 5 cm from the wire, the magnetic field is B. The field at 20 cm from the wire would be :
1.
2.
3.
4.
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