AQA A-Level Physics Paper 1, November 2020: Question 11

1 mark · Easy difficulty · Multiple Choice

Identify the physical quantity measured in kilowatt-hours (kW h).

Practise this question

Question

Multiple choice question 11 asking 'What quantity is measured in kW h?' with options A (charge), B (current), C (energy), and D (power), each accompanied by a selection box.
Question text

11 What quantity is measured in kW h?

[1 mark]

A charge

B current

C energy

D power

Mark scheme

Show the mark scheme Mark scheme indicating the correct answer for question 11 is C.

11 C

How to answer it

Identifying Units of Electrical Quantities

What this question tests

This question tests your recall and understanding of standard derived SI units and commercial energy units in physics, specifically distinguishing between power (rate of energy transfer) and energy itself.

Question 1.1 [1 mark]

What quantity is measured in kW h?

✅ Correct Answer

C: energy

1 mark awarded for selecting option C.

💡 Key Knowledge

  • Power is measured in watts (W) or kilowatts (kW), where 1 kW = 1000 W (Joules per second).
  • Since Energy = Power × time , multiplying kilowatts (kW) by hours (h) gives a unit of electrical energy.
  • 1 kW h is the amount of energy used by a 1 kW appliance running for 1 hour .

🧠 Exam Technique

Break down compound units using definitions you already know. Look at the formula E = P × t . Power ( P ) has units of kW, and time ( t ) has units of hours (h). Therefore, kW × h must be a unit of energy!

❌ Common Errors

Students often mistakenly choose D (power) because the unit contains "kW" (kilowatts), which is a unit of power. Always check dimensional/unit formulas ( Power × time = Energy ) rather than just looking at the prefix.

Topics

Physics · 3.1 Measurements and their errors · 3.5 Electricity

Question and mark scheme from the AQA A-Level Physics examination, Paper 1, November 2020. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.