Question

An electron moving with velocity 'v' enters a magnetic field as shown in the above figure.
Identify the path followed by the electron ?

• A. parabola
• B. straight line
• C. spiral or helix
• D. hyperbola
• E. circle

Answer 1

The correct option is C spiral or helix

When the given velocity is resolved into its components, the component of velocity that is perpendicular to magnetic field B is responsible for the magnetic force. This force acts as the centripetal force thereby giving the charge a circular motion.

Whereas the component of the velocity that is along the direction of the magnetic field, drags the charge in its direction.

The overall effect of these motions causes the charge to follow a spiral or helical path.
Therefore option C is correct.