Answer Happy

Problem 3: Discharging a capacitor in a magnetic field A A parallel plate capacitor with plates of area A sepa- rated by a small distance d along the z axis generates a uniform electric field E = E2 between the plates. A uniform magnetic field B = B is applied parallel to the plates. X (a) Find the total electromagnetic momentum in the space between the plates. (b) The capacitor is slowly discharged through a resistive wire connecting the plates along the z axis. The current in the wire experiences a magnetic force. Find the total impulse delivered by this force, and compare with the total momentum that you found in (a). B (c) What if the magnetic field is turned off instead? Does the changing magnetic field produce a net force on the capacitor? In which direction? How much impulse does this force deliver? HINT: Consider the net force on a thin slice of the capacitor between x and + Ar and show that it is proportional to an emf & that you can calculate using Faraday's law. Add up all the force on all the slices. 2 100 B