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