Question

Define Capacitance of a capacitor and its SI unit.

Answer 1

Hint: First of all we will discuss the capacitor then its property of capacitance that it exhibits. A capacitor in an electric circuit acts as a storage device for charges. It is the device which blocks the DC current in the circuit and behaves as an open circuit in DC circuit.

Complete step-by-step solution -
Capacitor- It is a device made of two parallel plates and a dielectric material kept in between. When we apply a voltage across these two plates then charge is stored in the plates an electric field is created and thus energy is stored in the electric field.

Capacitance - Capacitance is the effect of capacitor. It is the capacity of the capacitor to store charge in it.
Or
The capacitance is the charge which is deposited on the plates of a capacitor to establish a potential difference of 1 volt over it. Thus, the charge and voltage of a capacitor are directly related. The total charge in the capacitor is directly proportional to the voltage produced in the capacitor.
Mathematically,
$C = \dfrac{Q}{V}$
$Q = $ Charge of the capacitor in Coulomb
$V = $ Voltage applied in volts
$C = $ Capacitance of the capacitor

Thus from the equation we can say that capacitance is the amount of charge stored per unit applied voltage
Its SI unit is farad (F) named after scientist Michael faraday.
1 Farad- When a voltage difference of 1 volt is applied across the plates of a capacitor that has a charge of 1 coulomb then the capacitance of the capacitor is said to be 1 Farad.

Note: Capacitors are used commonly nowadays in electrical as well as electronic equipment for the purpose of filtering, smoothing the voltage etc. Capacitors are used as energy storage devices in the circuit apart from these the capacitor are also used for noise filtering, signal coupling and decoupling in an electric or electronic circuit.