A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is 'C' then the resultant capacitance is

(a) (n+1) C

(b) (n -1 )C

(c) nC

(d) C

(b) As n plates are joined, it means (n-1) combination joined in parallel.

Each plate is taking part in the formation of two capacitors except the plates at the ends. These capacitors are in parallel and n plates form (n -1) capacitors.Thus, equivalent capacitance between A and B = (n -1) C