Question

Effective capacitance between A and B in the figure shown is (all capacitances are in $\mu F$):

• A. $\frac{3}{14}\mu F$
• B. $\frac{14}{3}\mu F$
• C. $21\mu F$
• D. $23\mu F$

Answer 1

The correct option is B $\frac{14}{3}\mu F$

The combination is a wheatstone bridge. Hence the $2\mu F$ capacitor can be neglected.

Now there are two branches of series capacitances $3\mu F$ and $6\mu F$, and $4\mu F$ and $8\mu F$.

Equivalent capacitance of first branch=$\frac{3\times 6}{3+6}\mu F=2\mu F$

Equivalent capacitance of second branch=$\frac{4\times 8}{4+8}\mu F=\frac{8}{3}\mu F$

These capacitances are in parallel across AB.

Hence net capacitance across AB=$2\mu F+\frac{8}{3}\mu F=\frac{14}{3}\mu F$