Capacitor in Series and Parallel Voltage Explained

Capacitor in Series and Parallel Voltage Explained

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What happens to capacitor in series and parallel? Capacitors are connected together in series when they are daisy chained together in a single line and capacitors are connected together in parallel when both of its terminals are connected to each terminal of another capacitor. Before we connect number of capacitor in series and parallel. I will explain what effects if capacitor in series and parallel are connected.

When capacitors are connected together in parallel the total or equivalent capacitance, CT in the circuit is equal to the sum of all the individual capacitors added together. This is because the top plate of capacitor, C1 is connected to the top plate of C2 which is connected to the top plate of C3 and so on.

Capacitor in Series and Parallel Voltage Explained

Then, Capacitors in Series all have the same current flowing through them as iT = i1 = i2 = i3 etc. Therefore each capacitor will store the same amount of electrical charge, Q on its plates regardless of its capacitance.

This is because the charge stored by a plate of any one capacitor must have come from the plate of its adjacent capacitor. Therefore, capacitors connected together in series must have the same charge.

Capacitor in Series

Let us connect number of capacitors in series. V volt is applied across this series combination of capacitors.

capacitor in series

Let us consider capacitance of capacitors are C1, C2, C3…….Cn respectively, and equivalent capacitance of series combination of the capacitors is C. The voltage drops across capacitors are considered to be V1, V2, V3…….Vn, respectively.

Now, if Q coulomb be the charge transferred from the source through these capacitors, then:

Since the charge accumulated in each capacitor and I entire series combination of capacitors will be same and it is considered as Q.

Now, equation (i) can be written as:

Capacitors in Parallel

A capacitor is designed to store the energy in the form of its electric field, i.e. electrostatic energy. Whenever there is a necessity to increase more electrostatic energy storing capacity, a suitable capacitor of increased capacitance is required.

A capacitor is made up of two metal plates connected in parallel and separated by a dielectric medium like glass, mica, ceramics etc. The dielectric provides a non-conducting medium between the plates and has a unique ability to hold the charge, and the ability of the capacitor to store charge is defined as the capacitance of the capacitor.

When a voltage source is connected across the plates of the capacitor a positive charge on one plate, and negative charge on the other plate get deposited. The total amount of charge (q) accumulated is directly proportional to the voltage source (V) such that:


C is proportionality constant i.e. capacitance. Its value depends upon physical dimensions of the capacitor.


ε = dielectric constant,

A = effective plate area, and

d = space between plates.

Capacitors in Parallel

To increase the capacitance value of a capacitor, two or more capacitors are connected in parallel as two similar plates joined together joined together, then their effective overlapping area is added with constant spacing between them and hence their equivalent capacitance value becomes double (C ∝ A) of individual capacitance.

The capacitor bank is utilized in various manufacturing and processing industries incorporates capacitor in parallel, so to provide a capacitance of desired value as required by regulating the connection of capacitors connected in parallel and thus it is utilized efficiently as a static compensator for the reactive power balance in power system compensation.

When two capacitors are connected in parallel then the voltage (V) across each capacitor is same i.e. (Veq = Va = Vb) and current( ieq ) is divided into two parts ia and ib. As it is known that:

Putting the value of q from equation (1) in the above equation,

The later term becomes zero (as capacitor’ capacitance is constant). Therefore,

Applying Kirchhoff’s Current Law at the incoming node of the parallel connection:

Finally we get:

Hence, whenever n capacitors are connected in parallel the equivalent capacitance of the whole connection is given by following equation which resembles similar to the equivalent resistance of resistors when connected in series.

Capacitor in Series and Parallel Conclusion

After going through the above what effects if capacitors are connected in series and parallel we can now establish connecting number of capacitor in series and parallel. I hope you enjoy when reading this article, thank you.