Exam-style question
Try this first
A light bulb uses 240 J of energy in 2 minutes. What is its power rating?.
- A.2 W
- B.4 W
- C.12 W
- D.20 W
Model answer
What a good answer should say
- 2 W.
- the correct option
Explanation
Why this works
The correct answer is 2 W. This supports Calculate power as the rate of energy transfer.
in Work, energy and power because it uses the required mechanics relationship directly. The other options are less suitable because they confuse a different force, motion, energy, momentum, or materials concept.
Common mistake
No common mistake is linked to this question yet.