Question: An electric potential of 1000V is placed across two plates separated by 20mm, as shown in Fig. A beam of particles each with charge q and mass m travels at v = 3×106 m/s between the plates and is deflected downward. A uniform magnetic field applied to the region between the plates brings the beam back to zero deflection.
a. What is the magnitude and direction of the deflecting electric field E?
b. What is the magnitude and direction of the deflecting magnetic field B?
c. Prove that v = E/B when the electric and magnetic forces balance.
Fig. - Arrangement for electric deflection