Question

A composite parallel plate capacitor is made up of two different dielectric materials with different thickness($t_{1}and{t}_2$) as shown in figure. The two different dielectric materials are separated by a conducting foil F. The voltage of the conducting foil is

• A. 52 V
• B. 60 V
• C. 67 V
• D. 33 V

Answer 1

The correct option is B 60 V

Ans : (b)

$C_1=\frac{{\epsilon }_{r1}{\epsilon }_{0}A}{t_1}$
$C_2=\frac{{\epsilon }_{r2}{\epsilon }_{0}A}{t_2}$
Let voltage on the conductor foil is V, then
$C_1(100-V)=C_{2}V$
(Charges on both capacitors are equal)
$\frac{{\epsilon }_{r1}}{t_1}(100-V)=\frac{{\epsilon }_{r2}}{t_2}V$
$6(100-V)=4V$
$\therefore V=\frac{600}{10}=60$Volts