Question

Equivalent capacitance of the given combination of five capacitors is:

• A. 4 $\mu F$
• B. 10 $\mu F$
• C. 8 $\mu F$
• D. 120 $\mu F$

Answer 1

Answer: (A)

The given circuit can also be made in the following way.
This is just like Wheat stone bridge. As the bridge is balanced $\left(\frac{4}{4}=\frac{4}{4}\right),$ there will be no effect on $\text{10 }\text{F}$ capacitor. Equivalent capacitance in upper arm $C=\frac{4\times 4}{4+4}=\frac{16}{8}=2\mu F$ Equivalent capacitance in lower arm $C=\frac{4\times 4}{4+4}=\frac{16}{8}=2\mu F$ Now C and C" are connected in parallel, their net capacitance will be $C=C+C=2+2=4\mu F$