Question

Find equivalent capacitance between points A and B :

• A. $\frac{5C}{3}$
• B. $\frac{4C}{3}$
• C. $C$
• D. $2C$

Answer 1

The correct option is B $\frac{4C}{3}$

The corresponding equivalent circuit is as shown in figure.

The all capacitors on top are in series so the equivalent capacitance for top part is $C_t=(1/C+1/C+1/C{)}^{-1}=C/3$

Now this capacitance $C_t$ and bottom capacitance $C$ are in parallel.

So the equivalent capacitance $C_{AB}=C_t+C=C/3+C=4C/3$