A charged particle is moving with velocity `vecv` in a uniform magnetic field `vecB`. The magnetic force acting on it will be maximum when _____ .

Options

A. `vecvandvecB` are in same direction.
B. `vecvandvecB` are in opposite direction.
C. `vecvandvecB` are mutually perpendicular.
D. `vecvandvecB` make an angle of `45^(@)` with each other.

Answer

C

Explanation

Magnetic force on charged particle,
`vecF=q(vecvxxvecB)`
`thereforeF=qvBsintheta`
Where angle between `vecvandvecB` is `theta`.
When `vecv_|_vecB`, then `theta=90^(@)`
`thereforeF=qvBsin90^(@)`
`thereforeF=qvB` is maximum force.