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Question
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
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Solution
- Electrical energy = Electrical power × time.
- For practical applications, devices consuming high electrical power are used over a period of time.
- This leads to heavy expenditure of electrical energy. To measure such value of energy unit joule is significantly small.
Hence, unit kWh is used in practice. Unit 1 kWh represents power of 1 kW used for 1 hour and equals 3.6 × 106 J.
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