Same chapter3 marksDifficulty: Medium
State the principle of conservation of energy and give one example of its application.
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2 marksDifficulty: Medium
Define one kilowatt hour and express it in joules.
Original Khojo Papers practice question — not from a past board paper.
Answer
One kilowatt hour is the energy used by a device of power one kilowatt working for one hour. It equals 1000 × 3600 = 3.6 × 106 J.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
It is the commercial unit of electrical energy, and it is what a domestic electricity bill counts.
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