JEE Main202226 Jun 2022Evening ShiftPhysicsCapacitanceActual
A parallel plate capacitor with plate area A and plate separation d = 2 m has a capacitance of 4 μF . The new capacitance of the system if half of the space between them is filled with a dielectric material of dielectric constant K = 3 (as shown in figure) will be
Options
- A2   μF
- B32   μF
- C6   μF
- D8   μF
Correct answer
C. 6   μF
Step-by-step solution
This parallel plate capacitor can be divided into two capacitors. One with dielectric C 1 and other without dielectric C 2 . The two capacitors will be in series. Initially C = ε 0 A d = 4   μF Now, C 1 = k ε 0 A d 2 = 2 × 3 × ε 0 A d = 24   μF and C 2 = ε 0 A d 2 = 2 × ε 0 A d = 8   μF Finally C ' = C 1 C 2 C 1 + C 2 = 24 × 8 24 + 8 = 6   μF