TS EAMCET 04 May 2019 Shift 1 Solved Paper

Consider the below diagram.The circuit can be derawn as,
The equivalent of the above circuit is calculated as
Ceq=‌

C1C2

C1+C2

Substitute ‌

ε0A

d1

for C1 and ‌

ε0A

d2

for C2. in the above equation.
Ceq=ε0A[‌

‌ 1 d1 × 1 d2

1 d1 +‌ 1 d2

] =‌

ε0A

d1+d2

Substitute the given values in the above equation.
Ceq‌‌=‌

1

4π×9×109

×‌

36π×10−4

3×10−3+1×10−3

‌‌=‌

1

4

×10−10
‌‌=25pF