If both the plate area and the plate separation of a parallel-plate capacitor doubled, the capacitance is
Correct answer: C. Unchanged
- A. Doubled
- B. Halved
- C. Unchanged
- D. Triple
Explanation
The capacitance (C) of a parallel-plate capacitor is given by the formula C = (ε₀ * A) / d, where A is the area of the plates, d is the separation between the plates, and ε₀ is the permittivity of free space. When both the plate area (A) and the plate separation (d) are doubled, the new capacitance becomes C' = (ε₀ * (2A)) / (2d) = (ε₀ * A) / d = C. Thus, the capacitance remains unchanged.Option A is incorrect as it mistakenly assumes that only the area increase affects capacitance without accounting for the separation change. Option B incorrectly assumes that the increase in separation alone would reduce capacitance. Option D miscalculates the relationship entirely by suggesting an increase by a factor of three.
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