Capacitance
Key Stage 5
Meaning
Capacitance is the ability of a system to store an electric charge per unit of potential difference (pd), measured in farads (F).
About Capacitance
- The unit of capacitance is the farad (F), which is equal to one coulomb per volt.
- Factors affecting capacitance include the area of the plates, the distance between them, and the dielectric material between the plates.
- Capacitors in series have a reduced total capacitance, while those in parallel have an increased total capacitance.
- Capacitance is a measure of a capacitor's ability to store charge.
- In DC circuits, a capacitor charges and discharges, storing and releasing energy.
- In AC circuits, capacitors block direct current and allow alternating current to pass, acting as a reactive component.
Formula
The capacitance 𝐶 of a capacitor is given by:
𝐶=𝑄𝑉
Where:
𝐶 is the capacitance of the capacitor
𝑄 is the charge stored in the capacitor
and
𝑉 is the potential difference across the capacitor.
Examples
- A parallel-plate capacitor consists of two conductive plates separated by an insulating material.
- Used in electronic circuits to store energy, filter signals, and in timing applications.