How does a capacitor work and how do I treat it in a circuit?

for a capacitor the equations you need to know are:  Q=CV  V=Vin*e^(t/RC) and E=1/2QV (with Q=charge/columbs, C= capacitance/Farads, V=voltage/volts, R=resitance/ohms, Vin=initial voltage when discharging/volts, E=energy/joules)

The first equation describes the charge across a capacitor for a given voltage and the second equation describes the voltage, at a given time after the initial voltage, across a capcitor when it is discharging.

The basic function of a cpacitor is to store energy in the form of charge. A capcitor is made up of two plates that can hold electrostatic charge and they are separated by an insulating material. When a capacitor is connected across a battery current will flow and cause elctrons to leave one of the plates and to arrive at the other, hence creating a charge imbalance. This continues until the voltage ( as described by the first equation above ) equals the voltage of the battery.

A diagram of a capacitor and a circuit diagram could be used here to enhance the explanation. 

TM
Answered by Tom M. Physics tutor

2545 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

Explain how resonance occurs for a driven oscillating system and describe the effect of damping on the resonant frequency.


What does a negative velocity mean?


What is "half-life"?


A nail of mass 7.0g is held horizontally and is hit by a hammer of mass 0.25kg moving at 10ms^-1. The hammer remains in contact with the nail during and after the blow. (a) What is the velocity of the hammer and nail after contact?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning