Heat Engines and Refrigerators
Physics ⇒ Heat and Thermodynamics
Heat Engines and Refrigerators starts at 11 and continues till grade 12.
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A Carnot engine absorbs 1000 J of heat from a reservoir at 500 K and rejects heat to a reservoir at 300 K. How much work does it do?
A Carnot engine operates between 400 K and 300 K. What is its efficiency?
A Carnot refrigerator operates between 273 K and 313 K. What is its coefficient of performance (COP)?
A heat engine has an efficiency of 30%. If it absorbs 1500 J of heat, how much work does it do?
A heat engine operates between 500 K and 300 K. What is the maximum possible efficiency?
A heat engine receives 2000 J of heat from a hot reservoir and does 600 J of work. How much heat is expelled to the cold reservoir?
A heat pump delivers 3000 J of heat to a house for every 1000 J of work input. What is its COP?
A refrigerator has a COP of 4. If it removes 800 J of heat from the cold reservoir, how much work does it require?
A refrigerator removes 1200 J of heat from its cold reservoir and expels 1800 J to its hot reservoir. How much work does it require?
Describe the main difference between a heat engine and a refrigerator.
Describe the role of the working substance in a heat engine.
Explain why a refrigerator must do work to transfer heat from a cold region to a hot region.
Explain why no real engine can be 100% efficient.
Explain why the Carnot cycle is considered the most efficient cycle for a heat engine.
If a heat engine absorbs 500 J of heat from the hot reservoir and rejects 300 J to the cold reservoir, what is its efficiency?
The work output of a heat engine is equal to the difference between the heat absorbed from the hot reservoir and the heat rejected to the cold reservoir. State this relationship as a formula.
Which law of thermodynamics sets the upper limit for the efficiency of heat engines?
A Carnot refrigerator extracts 500 J of heat from a cold reservoir at 260 K and expels heat to a hot reservoir at 310 K. Calculate the minimum work required to operate the refrigerator for one cycle.
A certain heat engine absorbs 2500 J of heat from a high-temperature reservoir and rejects 1800 J to a low-temperature reservoir in each cycle. Calculate the efficiency of the engine and the work done per cycle.
A heat engine operates between a hot reservoir at 600 K and a cold reservoir at 350 K. If the engine absorbs 1800 J of heat from the hot reservoir in each cycle, what is the maximum possible work it can perform per cycle?
