A capacitor stores charge Q at potential difference ΔV. What happens if the voltage applied to the capacitor by a battery is doubled to 2 ΔV?
Correct answer: D. The capacitance remains the same, and the charge doubles
- A. The capacitance falls to half its initial value, and the charge remains the same
- B. Th capacitance and the charge both fall to half their initial values
- C. The capacitance and the charge both double
- D. The capacitance remains the same, and the charge doubles
Explanation
Since the capacitor an its nature is not changed, the capacitance must remain constant. In the equation: C = ΔQ/ΔV, if C (capacitance) is a constant, then ΔQ (charge stored) and ΔV (potential differencce) are directly proportional. Hence if ΔV doubles, then charge stored also doubles.
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About Capacitors
Capacitors store electric charge and energy in an electric field between conductors. Work includes capacitance, the relation Q = CV, dielectric materials, charging and discharging, energy formulas, and combinations of capacitors in series and parallel. Electric potential difference is needed to understand why charge and stored energy change.
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