Describe the following problem in detail-
Problem 1- What is the velocity of a beam of electrons that goes undeflected when moving perpendicular to an electric and magnetic fields, E and B are also perpendicular to each other and have magnitudes 7500V/m and8.9×10?3T , respectively.
Problem 2- What is the radius of the electron orbit if the electric field is turned off?
I need explain in brief of the above problem.