Have an account?
Skip to Content
Build your own quiz
Suggestions for you
15 questions
Show Answers
See Preview
- 1. Multiple Choice
A kettle uses 100J of electrical energy to produce 7J of sound energy and 93J of thermal energy. How efficient is the kettle?
100%
7%
93%
95%
- 2. Multiple Choice
A washing machine uses 250J of electrical energy to produce 125J of useful energy. How efficient is it?
5%
50%
55%
100%
- 3. Multiple Choice
A hairdryer uses 300J of energy to produce 60J of sound energy and 240J of thermal energy. Calculate it's efficiency.
80%
90%
20%
100%
- 4. Multiple Choice
An iPhone charger coverts 75J of electricty in to 50J of charge and 25J of thermal energy. How efficient is the charger?
10%
100%
33%
67%
- 5. Multiple Choice
What type of device might this Sankey be about?A very efficient LED light bulbA very inefficient incandescent light bulbA coal power plantA wind turbine - 6. Multiple ChoiceIf this household wanted to use less energy, where should they first focus their efforts.Water heaterBetter lightingUnplugging electronicsMore efficient air conditioning
- 7. Multiple ChoiceThe law of energy conservation says the total energy before the change _______ the total energy after itis less thanis more thanaffectsequals
- 8. Multiple Choice
Efficiency is calculated by useful energy output divided by total energy input, expressed as a percentage
False
True
- 9. Multiple ChoiceWhat is an energy transfer?DancingMovement of energyMovement of energy from one store to anothersomething moving
- 10. Multiple ChoiceIn energy transformations, "wasted energy" usually takes what form?heatchemical energylightsound waves
- 11. Multiple Choice
Which of these equations is correct?
- 12. Multiple ChoiceNo machine in existence has 100% efficiency due to ____________________.magicfrictionsmokeinput
- 13. Fill in the Blank
A __________ diagram shows the energy transfers in a system.
- 14. Fill in the Blank
Almost all objects lose energy in the form of __________.
- 15. Multiple Choice
Which bulb is the most efficient?
Filament bulb
LED light
CFL lamp
- Answer choicesTagsAnswer choicesTags