Question

An electron is traveling horizontally toward the north in a uniform magnetic field that is directed vertically downward. In what direction does the magnetic force act on the electron?
a.) west
b.) north
c.) east
d.) downward
e.) upward
f.) south

Answer 1

Answer:

e) upwrad z axis

Explanation:

To know the direction of the force we use the right hand rule.

The thumb points in the direction of the velocity, the fingers extended in the direction of the magnetic field and the palm of the hand in the direction of the force, this is for a positive charge if the charge is negative the force is in the opposite direction of The palm of the hand.

 

Let's apply to our case.

The thumb is in the x direction, the fingers in the vertical direction and since the electron has a negative charge, the force is on the z axis (perpendicular to the blade, coming out)

In general, in the nomenclature of the cardinal points the positive x-axis is the East, the positive y-axis is the North. Therefore the answer must be up on the z axis