MHT CET2019Evening ShiftPhysicsCapacitanceActual
In a parallel plate air capacitor the distance between plates is reduced to one fourth and the space between them is filled with a dielectric medium of constant 2. If the initial capacity of the capacitor is 4 μ F . then its new capacity is
Options
- A32 μ F
- B18 μ F
- C8 μ F
- D44 μ F
Correct answer
A. 32 μ F
Step-by-step solution
The capacitance of a parallel plate air capacitor is given by C 0 = ε 0 A d Where, ε 0 =permittivity of the medium, A = area of plates and d = distance between the plates When the distance between plates is reduced and a dielectric slab is introduced, then the capacitance becomes C = K ε 0 A d 1 … (ii) Where, K = dielectric constant of medium. Here, K = 2, d 1 = d 4 and C 0 = 4 μ F = 4 × 10 - 6 F From Eq. (ii), we get C = 4 K ε 0 A d 1 = 4 K ε 0 A d = 4 K C 0 …. (iii) [From Eq. (i)] Substituting given values in Eq.