Force on a charge in electric and magnetic fields
A charge particle follows a parabolic path in a uniform electric field and a charged particel moving in a uniform magnetic field has two kinds of motions
lnear motion in the direction of magnetic field and circular motion in a plane perpendicular to the magnetic field. when charge q is moving perpendicular to the magnetic field B, the radius of the circular path is `r=(mv)/(Bq)`. If v and B makes an angle `theta`, then `r=(mvsintheta)/(Bq)`, and the time period `T=(2pim)/(Bq)`.
When a charged particle q is moving with velocity `vecv` in a magnetic field `vecB`, the force is non-zero. It means.

Options

A. angle between them is either zero or `180^@`
B. angle between them is necessarily `90^@`.
C. angle between them can have any value other than zero and `180^@`
D. angle between them can have any value other than `90^@`.