Question

In the circuit diagram shown all the capacitors are in $\mu F$. The equivalent capacitance between points $A$ and $B$ is (in $\mu F$):

• A. $\frac{14}{5}$
• B. $7.5$
• C. $\frac{3}{7}$
• D. none of these

Answer 1

The correct option is A $\frac{14}{5}$

The dashed line part of the circuit indicates a balanced Wheatstone bridge so no current will pass through $10\mu F$ capacitor and we can remove the same from the circuit.
Here, $C_{63}=\frac{6\times 3}{6+3}=2\mu F$

and $C_{84}=\frac{8\times 4}{8+4}=\frac{8}{3}\mu F$

Thus, $C_{AB}=\frac{(2+8/3)\times 7}{(2+8/3)+7}$

$=\frac{14/3\times 7}{35/3}=\frac{14}{5}\mu F$