A charged particle is fired at an angle `theta` to a uniform magnetic field directed along the x-axis. During its motionalong a helical path, the particle will

Options

A. never move parallel to the x-axis
B. move parallel to the x-axis once during every rotation for all values of `theta`
C. move parallel to the x-axis at least once during every rotation if `theta= 45^(@)`
D. never move perpendicular to the x-direction.

Answer

A, D

Explanation

When the particle moves in a helical path, the plane of the helical path will be slightly inclinded with x-axis. Hence, option (a) and (d) are correct