← back to the Substrate Record
qid 12136 · engineering#
Question: The temperature inside a Carnot refrigerator is maintained at 5°C by rejecting heat to the surroundings at an ambient temperatureof 27°C. The inside temperature is now decreasedto-13°C, the ambient temperature remaining - constantat 27°C. Determine the percent increase in work inputfor the same quantity of heat removed.
- 65.7%
- 110.4%
- 75.3%
- 78.3%
- 120.8%
- 89.9%
- 94.5%
- 102.1%
- 85.2%
- 99.7%
Our answer: G. 94.5% Source quote machine-checked (exact quote)
A machine check confirms the quoted words appear at the source. A person has not yet reviewed these. EARN MARKS as a Human Reviewer
How it was answered
Stored method, replayed by code (kind: formula)
card: formula · card sha256 75cb8e180b95f933…
Current source
Wikipedia, "Coefficient of performance"
https://en.wikipedia.org/wiki/Coefficient_of_performance
“The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of the useful heating or cooling provided to the work (energy) required.”
Source quote machine-checked (exact quote)
retrieved 2026-09-18T01:08:16.751Z
page text sha256 34008aa771cbaad2… · content sha256 370464a82dd9379e…
addendum formula_qid12136.formula_ADDENDUM_source_rs20260918T010816Z · sha256 eb50c0ceca335443… · replaces the version below, addendum sha256 8736ee8d9e28d078…
Earlier version (superseded)
https://en.wikipedia.org/wiki/Coefficient_of_performance
Source weak (http_get_200_text_and_question_terms)
retrieved 2026-09-17T09:30:31.941Z
page text sha256 022ebbccaff4d9b2… · content sha256 —
addendum formula_qid12136.formula_ADDENDUM_source_bf20260917T093031Z · sha256 8736ee8d9e28d078… · replaces the version below, addendum sha256 7da0029b8af63fbc…
Earlier version (superseded)
No public source has been found for this card yet (2 places checked internally).
addendum formula_qid12136.formula_ADDENDUM_source · sha256 7da0029b8af63fbc…
If you have a Citable Source to dispute or challenge this, ADD IT so we can correct the answer by appending, never deleting. —
hello@lianabanyan.com