Q.
A gang capacitor is formed by interlocking a number of plates as shown in figure. The distance between the consecutive plates is 0.885 cm and the overlapping area of the plates is $5\ {cm}^{2}.$ The capacity of the unit is
A) 1.06 pF
B) 4 pF
C) 6.36 pF
D) 12.72 pF
Explanation
(b) The given arrangement of nine plates is equivalent to the parallel combination of 8 capacitors.
The capacity of each capacitor,
$C = \ \ \frac{\varepsilon_{0}A}{d}$
$= \ \frac{8.854 \times 10^{- 12} \times 5 \times 10^{- 4}}{0.885 \times 10^{- 2}} = 0.5pF$
Hence, the capacity of 8 capacitors
$= 8C = 8 \times 0.5 = 4\ pF$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.