Question

In the given figure, the capacitance C1, C3, C4, C5 have a capacitance 4 μF each. If the capacitor C2 has a capacitance 10μF, then effective capacitance between A and B will be

(a) 2 μF

(b) 6μF

(c) 4 μF

(d) 8 μF

Answer 1

Correct option (c) 4 μF

Explanation:

Capacitance of capacitors C1, C3, C4,C5 = 4 μF each and capacitance of capacitor C2 = 10 μF. If a battery is applied across A and B, the points b and c will be at the same potential (since C1 = C4 = C3 = C5 = 4 μF).

Therefore no charge flows through C2.

We have the capacitors C1 and C5 in series. Therefore their equivalent capacitance,

Similarly, C4 and C3 are in series. Therefore their equivalent capacitance,

Now C' and C are in parallel. Therefore effective capacitance between A and B = C' + C = 2 + 2 = 4 μF