There are two types of combinations of capacitor viz capacitors in parallel and capacitors in series. But another combination can be possible which is mix combination, it is the combination of series and parallel connection of capacitor. Capacitor combination equivalent is opposite to resistance capacitor stores charge and resistor drops charge series connection of resistors increase the equivalent value and series connection of capacitor decreases the equivalent value. Series connection is made to decrease the equivalent value of capacitor and parallel connection is used to increase the store capacity of capacitor. In parallel connection each capacitor can store charge according to its full capacity but in series connection it can not use its full capacity that’s why series connection is used to lower the equivalent capacitance value.
What is capacitor? Which stores charge is called capacitor. Capacitor stores capacity of charge. It is measured in Coulomb(C). Combination capacitors are used for special case. Arranging many capacitors for one purpose is called combination of capacitors. The whole combination is worked as one capacitor. There are two types of combinations
1. Series combination
2. Parallel combination
# Series combination: Normally connecting series capacitors is series combination. Series combination is that where all the capacitors connected serially. In parallel capacitors are connected in parallel combination. In series connection you have to connect one capacitor’s positive terminal to another capacitor’s negative terminal in this way the series combination is made for capacitor. There is only one common point between two capacitors.
Each capacitor has +Q and – Q charges between their two points.
If every capacitors potential difference are V1, V2, V3
Then capacitors voltage
V = V1 + V2 + V3 ……………. (i)
Capacitance of the capacitors are C1, C2 and C3
If we use an equivalent capacitor instead of the capacitors which potential difference is V and charge is Q.
For series capacitor
This is the series formula of capacitors. We use the equation when the capacitors in series.
Combination of parallel capacitor
Where all the capacitors Positive points are connected in a common point and negative points are connected in a common point or ground is capacitors in parallel combination. A figure is shown where capacitors positive points are connected with cell’s positive point and negative point are with its negative point. For making parallel connection there will be two common points between the capacitors all the positive terminal should be shorted in one point and all the negative terminal should be connected in one point then the connection is parallel.
If +Q charge is supplied, then the capacitors take charges across their capacitance.
Let, capacitor’s charges are Q1, Q2 and Q3
Total charge Q is
Q = Q1 + Q2 + Q3 ————- (i)
Each capacitor has same potential difference. Because their two points are connected with cell’s two points.
Consider, voltage v, capacitance of each capacitors are
C1 ,C2 ,C3
Then capacitors voltage and charge, Q1 = C1V , Q2 = C2V, Q3 = C3V ————- (ii)
Using equivalent capacitor which voltage is V and charge Q.
We can write
Cp = Q/V
Or, Q = CpV —————- (iii)
Substituting the values of equation (ii) & (iii) in (i)
CpV = C1V + C2V + C3V
Or, Cp = C1 + C2 + C3
For n number of capacitor parallel,
Cp = C1 + C2 + C3 + ————- + Cn
So, we can said that
Equivalent capacitor is the summation of capacitance of capacitors.
This is capacitor formula when connects parallel.