Question

A parallel plate capacitor with air between the plate has a capacitance of $15\, pF$ The separation between the plate becomes twice and the space between them is filled with a medium of dielectric constant $3.5$. Then the capacitance becomes $\frac{x}{4} pF$ The value of $x$ is _______

Answer 1

The correct answer is 105.
C0​=d∈0​A​=15pF
C=2dK∈0​A​=23.5​×15pF=4105​pF