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?

Question

Philoid · Accepted Answer

If the force is acting in the y-axis then the electron beam will be deflected from positive x-axis along y-axis. The electrons motion is in positive x-axis and then current will be along negative x-axis. And the force is acting along the y-axis. According to Fleming’s left hand rule the magnetic filed will be in z-axis. So we can conclude that the field is parallel to the z-axis.