{draw_block()}
\nA Carnot engine is in action. The temperature of its hot reservoir is {th} K, and the temperature of its cold reservoir is {tc} K
", "parts": [{"precisionPartialCredit": "50", "mustBeReduced": false, "minValue": "siground(efficiency,3)-siground(abs(efficiency/100),3)", "precisionMessage": "You have not given your answer to the correct precision.", "marks": "2", "extendBaseMarkingAlgorithm": true, "strictPrecision": true, "maxValue": "siground(efficiency,3)+siground(abs(efficiency/100),3)", "showPrecisionHint": true, "prompt": "Calculate the efficiency of the carnot engine, in percent to three significant figures.
", "precision": "3", "variableReplacementStrategy": "originalfirst", "type": "numberentry", "showFeedbackIcon": true, "notationStyles": ["plain", "en", "si-en"], "unitTests": [], "correctAnswerFraction": false, "precisionType": "sigfig", "scripts": {}, "mustBeReducedPC": 0, "customMarkingAlgorithm": "", "showCorrectAnswer": true, "allowFractions": false, "correctAnswerStyle": "plain", "variableReplacements": []}, {"precisionPartialCredit": "50", "mustBeReduced": false, "minValue": "siground(q_h,3)-siground(abs(q_h/100),3)", "precisionMessage": "You have not given your answer to the correct precision.", "marks": "2", "extendBaseMarkingAlgorithm": true, "strictPrecision": true, "maxValue": "siground(q_h,3)+siground(abs(q_h/100),3)", "showPrecisionHint": true, "prompt": "The work done by the Carnot cycle was {work} J. Calculate the amount of heat added to the system from the hot reservoir, to three significant figures.
", "precision": "3", "variableReplacementStrategy": "originalfirst", "type": "numberentry", "showFeedbackIcon": true, "notationStyles": ["plain", "en", "si-en"], "unitTests": [], "correctAnswerFraction": false, "precisionType": "sigfig", "scripts": {}, "mustBeReducedPC": 0, "customMarkingAlgorithm": "", "showCorrectAnswer": true, "allowFractions": false, "correctAnswerStyle": "plain", "variableReplacements": [{"must_go_first": true, "variable": "efficiency", "part": "p0"}]}], "name": "Carnot cycle efficiency", "variable_groups": [], "rulesets": {}, "preamble": {"js": "", "css": ""}, "advice": "a)
\n$Efficiency = (1-\\frac{T_c}{T_h})$ = 1-({tc}/{th}) = {siground(efficiency/100,3)}
\nSo the efficiency of the carnot cycle is {siground(efficiency,3)} %.
\nb)
\n$Efficiency = \\frac{useful\\,energy}{total\\,energy} = \\frac{work}{heat\\,from\\,hot\\,reservoir}$
\n$Q_h = \\frac{W}{eff} =$ {work} / {siground(efficiency/100,3)}
\nSo the heat extracted from the hot reservoir is {siground(q_h,3)} J.
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