Capacitor

How it is used

Capacitors are charged and discharged; the charge stored is Q = CV. Physics courses study how current and voltage change exponentially during charging and discharging, with a time constant RC. Values are usually in microfarads (μF).

Example sentences

1. The capacitor discharges through the resistor, and after one time constant the voltage has fallen to about 37% of its initial value.

2. A camera flash uses a capacitor to release a lot of energy very quickly.

Common collocations

• charge a capacitor
• discharge a capacitor
• capacitance
• time constant
• parallel-plate capacitor

Related terms

• electric chargeA basic property of matter that makes particles feel electric forces. Charge can be positive or negative; like charges repel and unlike charges attract. It is measured in coulombs (C).
• electric fieldThe region around a charged object where another charge feels an electric force. Its strength is the force per unit charge, measured in newtons per coulomb (N/C) or volts per metre (V/m).
• circuitA closed path through which electric current can flow, made of a power source, wires and components such as lamps, resistors and switches.
• voltageThe energy transferred to or by each coulomb of charge between two points in a circuit, also called potential difference. It is measured in volts (V).
• resistanceHow strongly a component or material opposes the flow of electric current. It equals voltage divided by current and is measured in ohms (Ω).

This word in other fields

The same English word can have a different meaning in another field:

• capacitor · Electrical & Electronics Engineering

More terms: Electricity and Magnetism

• electric current
• Ohm's law
• magnetic field
• electromagnetic induction
• electromotive force