The force `vecF` experienced by a particle of charge q moving with a velocity `vecv` in a magnetic field `vecB` is given by `vecF=q(vecvxxvecB)`. Which pairs of vectors are at right angles to each other?

Options

A. `vec(F) and vec(v)`
B. `vec(F) and vec(B)`
C. `vec(B) and vec(v)`
D. `vec(F) and (vec(v) xx vec(B))`

Answer

A, B

Explanation

The pairs `vec(F), vec(v) and vec(F), vec(B)` are always at right angle to each other, because `vec(F)` is always perpendicular to the plane containing `vec(B) and vec(v)`. Vector `vec(B) and vec(v)` may have any angle between them.