Question

A beam of photons (q = +1.6 x 10^-19 C) is moving with various speeds in the positive x direction (to the right). It enters a region where there is a uniform magnetic field of magnitude 0.25T pointing in the negative z direction (into the page).

a) The protons feel a force due to this magnetic field. Explain why, and indicate the direction of the force.

b) Not all protons will feel a force of the same magnitude. Why?

c) As a result of the magnetic force, the protons will deviate from their speed original direction towards the right. It is desired that those protons traveling at a speed of 1.75*10^5 m/s don't deviate at all and continue on a straight path to the right. This is to be achieved by turning on an electric field in the same region as the magnetic field. In what direction should the electric field point? Explain.

d) Find the magnitude of the electric field necessary to achieve the result of the previous question.

Answer 1