Chapter 27, Problem 27.29E

(a) What is the speed of a beam of electrons when the simultaneous influence of an electric field of 1.56 × 10⁴ V/m and a magnetic field of 4.62 × 10⁻³ T, with both fields normal to the beam and to each other, produces no deflection of the electrons? (b) In a diagram, show the relative orientation of the vectors $\stackrel{\to }{\text{v}}$, $\stackrel{\to }{\text{E}}$, and $\stackrel{\to }{\text{B}}$. (c) When the electric field is removed, what is the radius of the electron orbit? What is the period of the orbit?