Question

A. Find equivalent capacitance between A and B in the combination given below. Each capacitor is of 2 μF capacitance.
B. If a dc source of 7 V is connected across AB, how much charge is drawn from the source and what is the energy stored in the network?

Answer 1

A. The equivalent capacitance between A and B in the combination is 6/7 μF.

• In the above circuit, the first and the last capacitor are in series with each other and the other three resistors C2, C3 and C4 which are in parallel to each other.

• Now, the resultant capacitance of the three parallel capacitors C2, C3 and C4 is 6μF.

• The resultant capacitance of 6μF, C1 and C5 are in series.

• So, resultant capacitance = 7/6μF

B. As we know that the realtion between capacitance and voltage is given by-

Q = CV

• Hence, the charge drawn from the source is

Q = 7/6μF*7 = 6*10^-6 C

• And energy stored in the network is

E = CV^2/2 = 6*10^-6*49/7

E = 21*10^-6 J which is our required answer.

Answer 2

Answer

the required answer is 6C/11 for this network