Question

 A parallel plate capacitor with air between the plates has a capacitance of 9 pf. The separation between its plates is 'd' . The space between the plates is now filled with two dielectrics, one of the dielectric has dielectric constant k1 = 5 and thickness d/6 while the other one has dielectric constant k2 =10 and thickness 5d/6 , capacitance of the capacitor is now:​

Answer 1

Answer:

40.5pF

The air filled capacitance , C=

d

Aϵ

0

=9pF

According to question there are two capacitor with capacitances C

1

and C

2

. and they are in series .

Here, C

1

=

(d/3)

Ak

1

ϵ

0

=9

d

Aϵ

0

=9C as k

1

=3

and C

2

=

(2d/3)

Ak

2

ϵ

0

=9

d

Aϵ

0

=9C as k

2

=6

The equivalent capacitance, C

eq

=

C

1

+C

2

C

1

C

2

=

9C+9C

(9C)(9C)

=

2

9

C=(9/2)9=40.5pF