The energy stored in a charged capacitor is given by
Correct answer: B. half CV squared
- A. QV
- B. half CV squared
- C. CV
- D. half QC
Explanation
The factor of one half appears because the voltage rises from zero to V as the capacitor charges, so the average voltage during the process is half the final value. The expression can equally be written as half QV or as Q squared over 2C. This stored energy is what a camera flash releases in a few milliseconds.
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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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