Unit conversion check: How many watts are there in 40 kW?
Electrical Engineering
Energy and Power
Difficulty: Easy
Choose an option
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A0.4 mW
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B40,000 W
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C400 W
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D5,000 W
Answer
Correct Answer: 40,000 W
Explanation
Introduction / Context:Unit conversions between prefixes (kilo, milli, micro) are routine in electrical engineering. Correctly scaling quantities prevents design errors and misinterpretation of specifications or measurements.
Given Data / Assumptions:
- Power given: 40 kW.
- 1 kilowatt (kW) = 1,000 watts (W).
Concept / Approach:Apply the metric prefix conversion: multiply kilowatts by 1,000 to convert to watts. No additional calculations are needed.
Step-by-Step Solution:
40 kW = 40 * 1,000 W.Compute: 40 * 1,000 = 40,000 W.Therefore, 40 kW equals 40,000 W.Verification / Alternative check:Reverse conversion: 40,000 W / 1,000 = 40 kW. The operation is consistent both ways.
Why Other Options Are Wrong:
- 0.4 mW, 400 W, 5,000 W: Incorrect scaling; these do not match the kilo-to-watt conversion.
Common Pitfalls:
- Mistaking kilo (10^3) for milli (10^-3) leading to inversion errors.
Final Answer:40,000 W