A magnetic field ` vec(B) = B_(0)hat(j)` , exists in the region `a ltxlt2a` , and `vec(B) = -B_(0) hat(j)` , in the region `2a lt xlt 3a`, where `B_(0)` is a positive constant . A positive point charge moving with a velocity `vec(v) = v_(0) hat (i)` , where `v_(0)` is a positive constant , enters the magnetic field at `x= a` . The trajectory of the charge in this region can be like

Options

A.
B.
C.
D.

Answer

A

Explanation

`vecF_(m)=q(vecvxxvecB)`