Capacitance of a Parallel-Plate Capacitor?

📌 CONCEPT: Capacitance is the ability of a capacitor to store electric charge, measured in Farads (F).

📐 RULE / FORMULA: The capacitance (C) of a parallel-plate capacitor is given by the formula C = ε₀εᵣ(A/d), where ε₀ is the permittivity of free space, εᵣ is the relative permittivity of the dielectric material, A is the area of the plates, and d is the distance between the plates.

💡 WORKED EXAMPLE: If the original capacitance of the capacitor is 2.5 x 10⁻⁹ F and the area of the plates is 50 cm², what is the new capacitance if the distance between the plates is reduced to 1 mm and the dielectric material is replaced with a material of double the dielectric constant?

⚠️ COMMON MISTAKE: Students often forget to account for the change in dielectric constant when replacing the dielectric material, which can lead to incorrect capacitance values.