Physics Work & Energy NUMS 2020
PMDC Verified Question 79 of 108
Kilowatt-hour is unit of:
A
Electric energy
B
Power
C
Momentum
D
Torque
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option A: Electric energy
Concept:

A unit formed by multiplying Power and Time always yields a measure of Energy.

Formula:

$$ E = P \times t $$

Solution:

  • Kilowatt (kW) is a unit of Power.


  • Hour (h) is a unit of Time.


  • Power \( \times \) Time = Energy.


  • 1 kWh = \( 1000 \text{ W} \times 3600 \text{ s} = 3.6 \times 10^6 \text{ Joules} \), which is the standard commercial unit of electrical energy.


Why other options are incorrect:

Students often see "Watt" and immediately assume Power. However, multiplying it by time converts it back to Energy.

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.

Previous Question All Work & Energy MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App