Question detail
A light bulb uses 240 joules of energy in 2 seconds. What is its power rating?
Try the question, check the answer, then read the explanation to understand the curriculum point.
At a glance
MCQ
Type
practice
Style
Topic
Energy changes in a system, and the ways energy is stored before and after such changes
Question
- A. 80 W
- B. 100 W
- C. 120 W
- D. 140 W
Answer
120 W
Explanation
The correct option is "120 W". 120 W is right because it directly matches Power: Calculate power using energy transferred divided by time.. The other options are less suitable because they change the required Physics relationship, confuse the relevant energy store or use a distractor that does not answer the question.
Common mistake
Common Mistake in Power Calculation
Students often confuse the formula for power, using work done instead of energy transferred.
Remember that power can be calculated using the formula: power = energy transferred / time. Ensure you use energy transferred when calculating power.
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