How much heat does a 40 W bulb generates in one hour ?
Correct answer: A. 144000J
- A. 144000J
- B. 144J
- C. 1.44J
- D. 14J
Explanation
Electrical energy is calculated from E = Pt: 40 W x 1 h x 3600 s/h = 144000 J. Option b, 144 J, results from forgetting that one hour contains 3600 s.
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