Question

An electron moving with velocity 'v' enters a magnetic field as shown in the above figure.
Identify in which direction, the electron will experience a force ?

• A. into the page.
• B. out of the page.
• C. toward the top of the page.
• D. toward the bottom of the page.
• E. to the left.

Answer 1

Answer: (B)

out of the page.

The component of the velocity that is perpendicular to the direction of the magnetic field influences the magnetic force acting on the charge.
Therefore from Fleming's-left hand rule the magnetic force for the given directions act into the plane of the page for a positive charge.

But the given charge in the question is negative, thus the magnetic force on this charge is acting out of the plane of the page.