Question

Three identical capacitors are connected together differently. For the same voltage to every combination, the one that stores maximum energy is:

• A. The three in series
• B. The three in parallel
• C. Two in series and the third in parallel with it
• D. Two in parallel and the third in series with it

Answer 1

The correct option is B The three in parallel

We know energy $=\frac{1}{2}C{V}^2$
For energy stored to be maximum, $C_{eff}$ of the three capacitors must be maximum.
When three are parallel, $C_{eff}=3C$
When three are series, $C_{eff}=\frac{C}{3}$
When two are in parallel and other in series, $C_{eff}=\frac{C}{2}+C=\frac{3C}{2}$
$\therefore C_{eff}$ is maximum when three of them are parallel.