Question

#1 Though air’s resistivity is very large, 3 × 1013 Ω · m, it isn’t a perfect electric insulator. This means that the charges on a capacitor can “leak” from one plate to another slowly causing the capacitor to discharge.

(a.) Assume that the air between the plates obeys Ohm’s law and treat the discharging capacitor as an RC circuit. Show that the time constant for a parallel-plate capacitor is independent of its geometry and therefore all air-filled capacitors take the same amount of time to discharge.

(b.) How long would it take in minutes for an air-filled parallel-plate capacitor to lose half of its initial charge?

Answer 1