Question

Find equivalent capacitance between A and B.

Answer 1

$\frac{1}{C_{eqv}}=\frac{1}{2}+\frac{1}{6}+\frac{1}{2}=\frac{7}{6}$

$C_{eqv}=\frac{6}{7}\mu f$

$Q=C_{eqv}V=\frac{6}{7}\times 7=6\mu c$

$E=\frac{1}{2}C{V}^2=\frac{1}{2}\times \frac{6}{7}\times 49=21J$