Physics Current Electricity MDCAT 2019
PMDC Verified Question 86 of 112
Calculate the rate at which energy is transferred by 220 V mains supply which provides a current of 0.1 A to a LED?
A
22 kW
B
22 W
C
2.2 kW
D
2.2 W
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: 22 W
Concept:

The rate at which energy is transferred is the definition of electrical power.

Formula:

$$ P = VI $$

Solution:

  • Given Voltage \( V = 220 \text{ V} \).


  • Current \( I = 0.1 \text{ A} \).


  • \( P = 220 \times 0.1 = 22 \text{ Joules/second} = 22 \text{ W} \).


Why other options are incorrect:

  • Opt A & C: Use kW (kiloWatts) incorrectly. 22W is 0.022 kW.


  • Opt D: Decimal placement error.

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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