An electron and a proton are moving on straight parallel paths with same velocity. They enter a semi infinite region of uniform magnetic field perpendicular to the velocity.
Which of the following statement(s) is /are true?

Options

A. They will never come out of the magnetic field region.
B. They will come out travelling along parallel paths.
C. They will come out at the same time.
D. They will come out at different times.

Answer

b, d

Explanation

Both the particles will complete half circle and then emerge back parallel to the initial direction of motion. Hence, option (b) is correct. Time taken to complete the circle inside magnetic field depends on mass of the particle also. Electron and proton have different masses, hence they will take different time to come out. Hence, option (d) is also correct.