A particle of mass m and charge Q moving with a velocity v enters a region on uniform field of induction B Then its path in the region is s

Options

A. its path in the region of the field is always circular
B. its path in the region of the field is circular if `vec(v). vec(B)= 0`
C. its path in the region of the field is a straight line if `vec(v) xx vec(B) = 0`
D. distance travelled by the particle in time T does not depend on the angle between `vec(v) and vec(B)`.

Answer

B, C, D

Explanation

If `vec(v).vec(B)= 0 rArr` force is `bot` to velocity
If `vec(v) xx vec(B) =0 rArr F=0` it is straight line.
`:.` Speed is constant