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 x 4 pF . The value of x is____.

Step-by-step solution

Capacitance of the parallel plate capacitor when air is present between the plates, C = ε 0 A d = 15   pF Capacitance of the parallel plate capacitor when dielectric is filled in between the plates, C ' = k ε 0 A d ' = 3 . 5 ε 0 A 2 d = 3 . 5 2 × 15   pF = 105 4   pF Therefore, x = 105 .