Question

An electron moving in the direction of the +x-axis enters a region where both an electric and magnetic field are applied. The electron moves through the two fields undeflected (with constant velocity). If the magnetic field is in the -y direction, what is the direction of the electric field in this region? An electron moving in the direction of the +x-axis enters a region where both an electric and magnetic field are applied. The electron moves through the two fields undeflected (with constant velocity). If the magnetic field is in the -y direction, what is the direction of the electric field in this region?

Answer 1

The electric field is entering the sheet

Step-by-step explanation:

When the electron enters the region with the two fields, each one feels a force, so that the direction of the electron is altered, the sum of these two forces is zero.

Let's look for the direction of the magnetic force, for a positive charge, using the rule of the right hand, where the thumb goes in the direction of the velocity of the particle, the fingers extended in the direction of the magnetic field and the palm is in the direction of the strength

Let us apply this rule our case, the thumb goes the x axis and the fingers on the Y axis, therefore, the force is coming out of the sheet, if the load were positive, but with negative the magnetic outside is entering the leaf

The electric force is F = q.E.

For the resultant to be zero the electric force must leave the sheet and as our charge is negative The electric field is entering the sheet