Physics Work & Energy NUMS 2022
PMDC Verified Question 60 of 108
One kilowatt-hour is equal to:
A
36 MJ
B
3.6 MJ
C
38 MJ
D
3.8 MJ
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: 3.6 MJ
Concept:

Convert the kilowatt-hour into Joules, then apply the correct SI prefix.

Formula:

$$ E = P \times t $$

Solution:

  • \( 1 \text{ kWh} = 1000 \text{ W} \times 3600 \text{ s} = 3,600,000 \text{ Joules} \).


  • The prefix for a million (\( 10^6 \)) is Mega (M).


  • Therefore, \( 3,600,000 \text{ J} = 3.6 \times 10^6 \text{ J} = 3.6 \text{ MJ} \).


Why other options are incorrect:

36 MJ would be \( 36 \times 10^6 \) J (10 kWh). 3.8 MJ is a purely fabricated number.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

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