An electron is moving along positive x-axis. To get it moving on an anticlockwise circular path in x-y plane, a magnetic field is applied

For the particle to move along anticlockwise path, force should be along j^. Velocity is along i^Now F→m=-e(v→×B→)In terms of unit vectors only,∣j^=-(i^×?^) or j^=?^×i^ Clearly, ?^ is k^. .