Question

A parallel plate capacitor has $91$ plates, all are identical and arranged with same spacing between them. If the capacitance between adjacent plates is $3pF$. What will be the resultant capacitance?

• A. $273pF$
• B. $30pF$
• C. $94pF$
• D. $270pF$

Answer 1

The correct option is D $270pF$

When $n$ plates are arranged with the same spacing between them, then the combination behaves as $(n-1)$ capacitors in parallel since charge on each plate is the same.

Hence, equivalent capacitance is $C_{eq}=(n-1)C$

Given, $n=91$ and $C=3pF$

$\therefore C_{eq}=3\times (91-1)=270pF$