Working Principle of a Capacitor
Definition of Capacitor
Fundamental Construction of Plate CapacitorCapacitor is constructed by using two conducting surfaces or plates and an insulating material (i.e., dielectric like mica, paper, air, etc.) inserted between these two plates.
Working of CapacitorAs a capacitor is a passive component, it does not generate any energy but it can store energy from an energy source like a battery or another charged capacitor.
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When we connect a battery (DC Source) across a capacitor, one plate (plate-I) gets attached to the positive end of the battery, and other plate (plate-II) gets attached to the negative end of the battery. Now, potential of that battery is applied across that capacitor. At that situation, plate-I is in positive potency with respect to the plate-II. At steady state condition, the current from the battery tries to flow through this capacitor from its positive plate (plate-I) to negative plate (plate-II) but cannot flow due to the separation of these plates with an insulating material.
An electric field appears across the capacitor. As time goes on, positive plate (plate I) will accumulate positive charge from the battery, and negative plate (plate II) will accumulate negative charge from the battery. After a certain time, the capacitor holds maximum amount of charge as per its capacitance with respect to this voltage. This time span is called charging time of this capacitor.
After removing this battery from this capacitor, these two plates hold positive and negative charge for a certain time. Thus this capacitor acts as a source electrical energy.
If two ends (plate I and plate II) get shorted through a load, a current will flow through this load from plate-I to plate-II until all charges get vanished from both plates. This time span is known as discharging time of the capacitor.