Which outcome decreases a heat engine's efficiency if the high-temperature reservoir undergoes a phase change resulting in a decreasing temperature?

💡 Explanation

Heat addition at decreasing temperature lowers engine efficiency, because Carnot efficiency depends on the temperature difference; therefore the overall efficiency drops rather than maintaining a high, constant temperature input.

• Which outcome occurs when a high-frequency voltage is applied to a piezoelectric crystal within a capacitance proximity sensor?
• Which mechanism limits the strength of thermosetting polymers with extensive cross-linking?
• Which operational limit is reached when a multi-stage Carnot heat engine encounters irreversible heat transfer?
• Which consequence results when surface plasmon resonance increases bandgaps during aluminum gallium arsenide fabrication?
• Which outcome results when uranium isotopes absorb neutrons?
• Which outcome occurs when contaminants alter thin-film optical coatings?