Two charged particles traverse identical helical paths in a completely opposite sense in a uniform magnetic field
1. | They have equal components of momenta. |
2. | They must have equal charges. |
3. | They necessarily represent a particle-antiparticle pair. |
4. | The charge to mass ratio satisfy: |
Biot-Savart law indicates that the moving electrons (velocity ) produce a magnetic field such that:
1. | . |
2. | . |
3. | it obeys inverse cube law. |
4. | it is along the line joining the electron and point of observation. |
1. | The magnitude of the magnetic moment now diminishes. |
2. | The magnetic moment does not change. |
3. | The magnitude of B at (0, 0, z), z >>R increases. |
4. | The magnitude of B at (0, 0, z), z >>R is unchanged. |
1. | The electron will be accelerated along the axis. |
2. | The electron path will be circular about the axis. |
3. | The electron will experience a force at 45° to the axis and hence execute a helical path. |
4. | The electron will continue to move with uniform velocity along the axis of the solenoid. |
1. | independent of which orbit it is in. |
2. | negative. |
3. | positive. |
4. | . | increases with the quantum number
Consider a wire carrying a steady current placed in a uniform magnetic field perpendicular to its length. Consider the charges inside the wire. It is known that magnetic forces do no work. This implies that,
(a) | the motion of charges inside the conductor is unaffected by since they do not absorb energy. |
(b) | some charges inside the wire move to the surface as a result of . |
(c) | if the wire moves under the influence of , no work is done by the force. |
(d) | if the wire moves under the influence of , no work is done by the magnetic force on the ions, assumed fixed within the wire. |
Choose the correct option:
1. (b), (c)
2. (a), (d)
3. (b), (d)
4. (c), (d)
(a) | |
(b) | the value of is independent of the sense of . |
(c) | there may be a point on where and are perpendicular. |
(d) | vanishes everywhere on . |
Which of the above statements is correct?
1. | (a) and (b) | 2. | (a) and (c) |
3. | (b) and (c) | 4. | (c) and (d) |
A cubical region of space is filled with some uniform electric and magnetic fields. An electron enters the cube across one of its faces with velocity and a positron enters via the opposite face with velocity . At this instant,
(a) | the electric forces on both the particles cause identical accelerations. |
(b) | the magnetic forces on both the particles cause equal accelerations. |
(c) | both particles gain or lose energy at the same rate. |
(d) | the motion of the centre of mass (CM) is determined by alone. |
Choose the correct option:
1. (a), (b), (c)
2. (a), (c), (d)
3. (b), (c), (d)
4. (c), (d)
A charged particle would continue to move with a constant velocity in a region wherein,
1. | |
2. | |
3. | |
4. |
Choose the correct option:
1. (a), (c)
2. (b), (d)
3. (b), (c), (d)
4. (c), (d)