question_answer

In this diagram, the P.D. between A and B is 60 V. The P.D. across \[6\mu F\] capacitor is ...V

A)  \[10\]    

B)  \[5\]     

C)  \[20\]   

D)  \[4\]

Correct Answer: A

Solution :

In the given figure \[3\mu F\] and \[3\mu F\] are in parallel Their equivalent capacitance is \[6\mu F\]. The equivalent circuit is as shown in the figure. The equivalent capacitance between A and B is \[\frac{1}{C}=\frac{1}{6}+\frac{1}{3}+\frac{1}{6}+\frac{1}{3}=\frac{1+2+1+2}{6}=\frac{6}{6}\] or  \[C=1\mu F\] Charge in the circuit, \[Q=CV=(1\mu F)(60V)=60\mu C\] The potential difference across \[6\mu F\] capacitor is \[=\frac{60\mu C}{6\mu F}=10V\]