Exercise
Form 10: Energy Diagrams and Efficiency
In this engaging exercise, students will explore energy diagrams to visualize energy transformations in various systems while analyzing the concept of efficiency to understand how energy loss can affect performance. Through hands-on activities and real-world examples, learners will apply their knowledge to optimize processes and calculate efficiency ratings.
Questions
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MultiChoice
How is energy efficiency calculated for a machine?
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MultiChoice
A light bulb consumes 100 J of electrical energy and produces 15 J of light energy. What is its efficiency?
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MultiChoice
In a Sankey diagram showing energy transformations, what does the width of an arrow represent?
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MultiChoice
In a energy flow diagram, wasted energy is usually shown branching off in which direction?
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MultiChoice
If an electric motor receives 200 J of electrical energy and loses 40 J as heat, how much useful mechanical work does it perform?
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MultiChoice
What is the efficiency of the motor in the previous question (160 J useful output from 200 J input)?
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MultiChoice
Why are LED lights much more efficient than traditional incandescent light bulbs?
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MultiChoice
According to the Law of Conservation of Energy, in any energy flow diagram, Total Input Energy must equal:
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MultiChoice
An engine has an efficiency of 25%. If it receives 1,000 J of chemical energy from fuel, how much energy is wasted?
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MultiChoice
Which design modification would increase the energy efficiency of a bicycle?
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MultiChoice
What happens to the total energy in a Sankey diagram if efficiency improves?
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MultiChoice
If a machine claims to have an efficiency of 110%, why is this claim impossible?