ENSC 2213 Thermodynamics Practice Exam 3 - Prof. Afshin Ghajar, Exams of Thermodynamics

Download ENSC 2213 Thermodynamics Practice Exam 3 - Prof. Afshin Ghajar and more Exams Thermodynamics in PDF only on Docsity! DISCUSSION SECTION # NAME ENSC 2213 THERMODYNAMICS PRACTICE EXAM – EXAM 3 Instructions for taking examinations 1. Do not open the exam until you are told to do so. When told to start, put your name on each page and your discussion section number in the space provided above. 2. This test is open book, open syllabus and one page of notes. You may also use the “Road Map” for properties. 3. Do not exchange anything with your neighbors during the exam. 4. Show all work. Use diagrams and show control volumes as needed! Identify reference points clearly and unambiguously. Write equations in variable form before entering numbers. Answers that are unsupported will not be accepted. Cross out (clearly) or erase all work that you do not want to be graded. 5. All answers should be given to a reasonable degree of precision - usually to three significant figures. 6. Every answer must include correct units. 7. Identify your final answer by boxing it in. 8. The examination will be stopped promptly at the appropriate time. Stop writing when told to do so and pass the exam papers towards the aisle immediately. 9. Unless you finish prior to 5 minutes before the exam finish time, please remain in your seat until all exam papers have been picked up. 10. The number in parentheses in each problem indicates the number of points for that problem. Note that problems may not be of equal weight. Good luck on the exam! ENSC 2213 Thermodynamics NAME PRACTICE EXAM 3 (25) Problem 1. A household refrigerator operates at steady state in an environment (kitchen) at 25ºC. The refrigerator has a coefficient of performance of 4.0 and rejects 5.0 kW by heat transfer to its surroundings (kitchen air) from metal coils located on its exterior. For this refrigerator determine: (a) The power input (kW). (b) The lowest theoretical temperature inside the refrigerator (ºC).