When 4 volts e.m.f. is applied across a 1 farad capacitor, it will store energy of_____________?
Correct answer: D. 8 joules
- A. 2 joules
- B. 4 joules
- C. 6 joules
- D. 8 joules
Explanation
Capacitor energy is W = ½CV² = ½ × 1 × 4² = 8 joules. The factor ½ is essential, so 4 joules would incorrectly equal CV² without this factor.
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