Identify the incorrect statement from the options below?
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Answer: A. Temperature of medium being cooled must be below that of the evaporator
Explanation
Heat transfer requires a natural temperature gradient, meaning the medium being cooled must be warmer than the evaporator. If the medium temperature were below the evaporator, heat would flow in the wrong direction, violating thermodynamic laws. This fundamental physical principle governs all refrigeration heat exchange processes across domestic and industrial equipment. The second law of thermodynamics dictates that heat energy flows spontaneously only from high-temperature regions to low-temperature regions. Refrigeration systems use mechanical work to pump heat uphill from a cold space to a warmer ambient environment. Evaporators absorb heat from the refrigerated space by maintaining a refrigerant saturation temperature lower than the conditioned medium.
Option B is a true statement because refrigerants must leave condensers in a liquid state to prepare for expansion. Option C correctly notes that solar thermal absorption systems often operate intermittently based on available solar radiation. Option D is valid because frost accumulation acts as an thermal insulator, severely reducing evaporator heat transfer efficiency.
- Subject
- Engineering
- Category
- Mechanical Engineering
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- —
- Difficulty
- medium
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