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COMEDK202510 May 2025Evening ShiftPhysicsCapacitanceActual

When a dielectric slab of dielectric constant k =2 is used to fill the space between the plates of a parallel plate capacitor, the capacitance of the capacitor is found to be 20 F . What will be the capacitance when the slab is replaced with air?

Options

  1. A40 F
  2. B20 F
  3. C5 F
  4. D10 F

Correct answer

D. 10 F

Step-by-step solution

The capacitance of a parallel plate capacitor filled with a dielectric material is given by the formula C = K C₀ , where C is the capacitance with the dielectric, K is the dielectric constant, and C₀ is the capacitance with air as the medium. Given C = 20 F and K = 2 , we substitute these values into the equation: 20 F = 2 C₀ Solving for C₀ : C₀ = 20 F 2 = 10 F . Answer: 10 F

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