Question

Two parallel plate capacitors each of capacitance 40 micro farad are connected in series. The space between the plates of the capacitors is filled with the dielectric material of dielectric constant 4. Find the equivalent capacitance of the system

Answer 1

Capacitance of parallel plate capacitor = C = K ε A / d
          K = dielectric constant of the medium between plates
            A = area of each plate 
         and d = distance between plates

Initially equivalent capacitance = 40 μF /2 = 20 μF   as they are connected in series.   When K =4,  each C becomes 160 μF.

hence the equivalent capacitance = 80 μF

Answer 2

32 microfarad is answer

Explanation:

1/40+(1/4(40))