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 \(v\) and a positron enters via the opposite face with velocity \(-v\). 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 \(\vec{B}\) alone. |
Choose the correct option:
1. (a), (b), (c)
2. (a), (c), (d)
3. (b), (c), (d)
4. (c), (d)
