Question

An electron beam projected along the positive x-axis deflects along the positive y-axis. If this deflection is caused by a magnetic field, what is the direction of the field? Can we conclude that the field is parallel to the z-axis?

Answer 1

Explanation:

• Towards the positive y-axis, the particle gets deflected.

• From this, we can conclude that on the particle, force is acting along the positive y-axis.

• Now, it can be assumed that the current be moving at the negative side, as now the electron is moving in the positive x-axis.  

• When Fleming’s left-hand rule is applied, in the current’s direction, we can find the thumb points, i.e., negative x-axis.

• As a consequence, the direction of the current is given by the forefinger, which is in the positive z-direction or on the paper plane.

• So, it can be concluded that at the positive z-axis, the magnetic field is pointed.