Question

An electron moves at 2.90×10⁶ m/s through a region in which there is a magnetic field of unspecified direction and magnitude 7.40×10^-2 T. What is the direction of the magnetic force experienced by the electron?

1) Upwards
2) Downwards
3) Leftwards
4) Rightwards

Answer 1

The direction of the magnetic force on an electron in a magnetic field depends on both the direction of the electron's velocity and the magnetic field. We use the right-hand rule to determine the direction, but without the relative directions, we cannot specify whether the force is upwards, downwards, leftwards, or rightwards.

Step-by-step explanation:

The direction of the magnetic force experienced by the electron depends on the direction of the magnetic field, the velocity of the electron, and the charge of the electron. To determine the direction of the force, we use the right-hand rule. For an electron (which has a negative charge), point your thumb in the direction opposite to the electron's velocity (since the electron is negative), your fingers in the direction of the magnetic field, and your palm will face the direction of the magnetic force on the electron. Without the specific direction of the magnetic field relative to the electron's motion, we cannot conclusively say which direction (upwards, downwards, leftwards, rightwards) the force is applied.