Question detail

If a heater has an efficiency of 75% and uses 4000 J of energy, how much energy is wasted?

Try the question, check the answer, then read the explanation to understand the curriculum point.

At a glance

MCQ

Type

practice

Style

Topic

Conservation and dissipation of energy

Question

  1. A. 1000 J
  2. B. 500 J
  3. C. 750 J
  4. D. 300 J

Answer

1000 J

Explanation

The correct option is "1000 J". 1000 J is right because it directly matches Energy transfers in a system: Use the term wasted energy to describe energy transferred in less useful ways.. 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

Misunderstanding Wasted Energy

Students often confuse wasted energy with energy that is simply lost, thinking it disappears rather than being transferred to less useful stores.

Clarify that wasted energy is energy that is transferred in ways that are not useful for the intended purpose, but it is still present in the system.

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