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Efficiency calculations
By Katie Bruce
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Last updated 5 months ago
20 questions
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Question 1
1.
A light bulb has a total energy input of 100 J and provides 20 J of useful light energy. Calculate the efficiency.
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Question 2
2.
A heater uses 500 J of energy and gives out 450 J of useful thermal energy. What is the efficiency of the heater?
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Question 3
3.
A fan uses 200 J of energy and produces 50 J of useful kinetic energy. Find its efficiency.
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Question 4
4.
A toaster has an energy input of 400 J and outputs 280 J as useful thermal energy. Calculate its efficiency.
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Question 5
5.
A television uses 600 J of energy, with 480 J being useful. What is the efficiency?
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Question 6
6.
An electric kettle has an input of 1000 J and outputs 800 J of useful thermal energy. Find its efficiency.
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Question 7
7.
A hairdryer uses 700 J of energy and outputs 490 J as useful thermal energy. Calculate the efficiency.
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Question 8
8.
A washing machine has a total energy input of 1200 J and produces 960 J of useful work. What is its efficiency?
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Question 9
9.
A blender uses 300 J of electrical energy and outputs 150 J of useful energy. What is the efficiency?
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Question 10
10.
A laptop consumes 400 J of electrical energy and produces 300 J as useful energy. Calculate the efficiency.
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Question 11
11.
A refrigerator uses 1500 J of energy, and 900 J is used for cooling purposes. What is the efficiency of the refrigerator?
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Question 12
12.
A microwave oven has an input energy of 2000 J and provides 1500 J as useful energy for heating food. Calculate the efficiency.
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Question 13
13.
A projector uses 500 J of electrical energy and outputs 350 J as useful light energy. What is its efficiency?
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Question 14
14.
A sound system consumes 600 J of energy, with 420 J being useful sound energy. Calculate the efficiency.
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Question 15
15.
A gaming console uses 800 J of electrical energy and 600 J of this is useful energy for processing and display. Find the efficiency.
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Question 16
16.
An electric vehicle uses 10,000 J of battery energy to produce 7,500 J of useful kinetic energy. Calculate the efficiency.
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Question 17
17.
A wind turbine generates 8,000 J of electrical energy from a total input of 10,000 J of wind energy. What is its efficiency?
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Question 18
18.
An industrial machine consumes 20,000 J of electrical energy and outputs 15,000 J as useful mechanical energy. Calculate its efficiency.
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Question 19
19.
A solar panel receives 12,000 J of solar energy and converts 4,800 J into electricity. What is the efficiency?
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Question 20
20.
A power plant uses 100,000 J of fuel energy and produces 35,000 J of electrical energy. Calculate the efficiency.
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