Question 21: One megawatt hour (MWh) is equal to: (Work, Power & Energy, power and energy)
Correct answer: D. 3.6 x 10⁹ J
- A. 3.6 x 10⁶ J
- B. 3.6 x 10¹² J
- C. 3.6 x 10⁸ J
- D. 3.6 x 10⁹ J
Explanation
Correct Answer: (d) 3.6 x 10⁹ J Explanation:1 MW = 10⁶ watts1 Wh = 1 watt-hour = 3.6 x 10³ JTherefore, 1 MWh = 10⁶ Wh x 3.6 x 10³ J/Wh = 3.6 x 10⁹ JIncorrect Options:(a) 3.6 x 10⁶ J: This option underestimates the energy by ignoring the conversion factor between watt-hours and Joules.(b) 3.6 x 10¹² J: This option overestimates the energy by using the wrong conversion factor for megawatts to Joules, ignoring the time factor.(c) 3.6 x 10⁸ J: This option uses an incorrect conversion factor for watt-hours to Joules, resulting in a slight underestimation.
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About Work and Energy
Work transfers energy when a force causes displacement, while kinetic energy, gravitational potential energy and power describe motion, position and the rate of energy transfer. The work-energy theorem links net work with change in kinetic energy, and efficiency accounts for energy losses rather than treating them as energy destruction.
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