Time constant of leaky dielectric capacitor – Rankers Physics
Topic: Capacitors
Subtopic: Charging and Discharging of Capacitors

Time constant of leaky dielectric capacitor

A capacitor is completely filled with a leaky dielectric. The capacitor is charged. It discharges with a time constant \(\tau = \rho k \epsilon_0\). The capacitor can be (Symbols have their usual meaning)
Parallel plate capacitor
Cylindrical capacitor
Spherical capacitor
Any of these

Solution:

For any capacitor geometry, capacitance is proportional to \(k\epsilon_0\) and resistance is proportional to resistivity \(\rho\), such that the shape factors cancel in \(\tau = RC = \rho k \epsilon_0\).

Leave a Reply

Your email address will not be published. Required fields are marked *