What is the direction of the velocity of a negative charge t

What is the direction of the velocity of a negative charge that experiences the magnetic force shown in each of the following three cases, assuming it moves perpendicular to

A) ...........?

B)............?

C).........?

Solution

Sol. A) Consider a cartesian coordinate system with magnetic field along z direction such that the direction coming out is positive and direction going inside is negative

From Fleming\'s left hand rule if Force is in positive y direction current flows in negative x direction, so electron will move towards positive x direction i.e. towards right

B.) If Force is along y direction, B is along x direction then current will be along z direction i.e. direction of electron will be along -z direction.

C) If Force is along -x direction, B is along -z direction then current will be along +y direction then electron motion will be along -y direction.