The following arrangement consists of four plates each of area A. the separation between the consecutive plates is d. what is the ratio of the effective capacitance between P and Q as shown in figures (1) and (2).

Options

A. 1
B. `2/3`
C. `3/2`
D. `4/3`

Answer

C

Explanation

The capacitance of each capacitor is `C=(epsi_(0)A)/(d)`
figure (1) can be redrawn as

This arrangement is equivalent to three capacitors joined in parallel.
`therefore`The effective capacitance is `C_(1)=3C=(3epsi_(0)A)/(d)` . . . (1)
Figure (2) can be redrawn as

this arrangement acts as a system of two capacitors joined in parallel.
`therefore`Their effective capacitannce `C_(2)=2C=(2epsi_(0)A)/(d)` . . . (2)
`therefore (C_(1))/(C_(2))=(3)/(2)`