Capacity of the conductor to hold the charge is called capacitance.Capacitance equation is the ratio of the total charge flowing across the conductor and the voltage applied across it. Capacitor is made up of two conducting plates separated by the dielectric medium.
Capacitance equation is given by
C = Q/V
Where, Q = Charge in the conductor,
V = Voltage applied across the conductor and
C = Capacitance.
The arrangement of the capacitor connected in a circuit.
1. If capacitors are connected in series,
the capacitance formula will be:
1/C = 1/C1 + 1/C2 + …….+ 1/Cn
2. If capacitors are connected in parallel,
the capacitance formula will be
C = C1 + C2 + …… + Cn
Where C1,C2,C3.......Cn are the capacitors.
Capacitance is represented by Farads “F”.
Example: Find capacitance if capacitors 8 F and 4 F are connected in series.
Solution: We have the equation for series connection of capacitors.
1/C = 1/C1 + 1/C2
So, C = (C1 x C2)/(C1 + C2)
= (8 x 4)/(8+4)
= 2.66 F
Example: Find capacitance if capacitors 5 F and 7 F are connected in parallel.
Solution: We have the equation for parallel connection of capacitors.
C = C1 + C2
= 5 + 7 = 12 F.