Answer with Explanation:
As a charged particle, the electron moves in a circular motion in a magnetic field because of a magnetic force that is perpendicular to its movement/travel (also known as velocity). This force doesn't affect the moving electron except for its motion; thus, the electron remains at constant or uniform speed. This is according to Fleming's rule regarding electrons.
Remember that this happens provided that the charged particle will move at right angle to the area of magnetic field.