Definition of Capacitance
Capacitance is the ability of a component to store electric charge. When a voltage is applied across a capacitor, it accumulates charge until it reaches a certain level. The amount of charge stored depends on the voltage and the capacitor’s plates electric field. Mathematically, it is expressed as:
C = Q / V
Where:
- C is the capacitance
- Q is the stored electric charge
- V is the voltage across the capacitor
Think of it like a water tank: the bigger the tank, the more water it can hold at a given pressure. In electronics, a larger capacity means more charge storage at the same voltage.
Units of Measurement
charge holding Capacity is measured in different units, depending on the size of the component:
- Farad (F) – the large unit, rarely used for everyday parts
- Microfarad (μF) – common for many circuits
- Nanofarad (nF) – used in radio circuits and high-frequency applications
- Picofarad (pF) – found in very small or high-frequency components
How Capacitance Is Measured
Special instruments called LCR meters are used to measure capacitance accurately. They apply a small AC signal to the component and measure how it reacts. Correct measurement is vital, especially when designing circuits that need precise timing or filtering.
