36. 2 HP per ton of refrigeration is required to maintain the temperature of – 40 degree C in the refrigerator if the refrigeration cycle works on Carnot cycle. A standard ice point temperature corresponds to the temperature of (a) water at 0°C (b) ice … b) The evaporator in the system is located in direct contact with the material being refrigerated. Reason (R): Throttling is a constant enthalpy process. Q4. A hermetic compressor is a) A reciprocating compressor b) A thermodynamically efficient compressor c) A factory sealed unit containing motor and compressor d) None of the above. © Copyright 2016. The compressor is the mechanical heart of a refrigeration system. All these actions are in sequence. the work done by the compressor).. As can be seen, the better (more efficient) the refrigerator is when more heat Q … In vapour compression refrigeration system throttle valve is used and not expansion cylinder because the power produced by expansion cylinder is very low. Stored chilled water or stored ice in tanks is used to provide cooling in buildings during peak hours when high electric demand charges and electric energy rates are in effect. Compressor in a refrigeration system increases (a) Temperature and pressure (b) Temperature and volume (c) Pressure and volume (d) None (Ans:a) Reciprocating compressor is used in refrigeration when pressure difference between condenser and evaporator is (a) >1.5 bars (b) <1.5 bars (c) >3.5 bars (d) None (Ans:c) Reciprocating compressor … ... B Wet bulb temperature increases . A thorough understanding of the role of a refrigeration compressor … compressor. Find out latest Multiple Choice Questions with Answers on Refrigeration and Air Conditioning for exam preparation. While designing the refrigeration system of an aircraft, the prime consideration is that the . Therefore statement (b) is wrong. www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. Evaporator: This is the part of the refrigeration system that is doing the actual cooling. Ammonia does not mix freely with lubricating oil. true? Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. Refrigeration and Air Conditioning MCQ Questions 1-One ton of refrigeration is equal to (A) 21 KJ/min (B) 105 KJ/min (C) 210 KJ/min (D) 420 KJ/min 2-A low side float valve maintains the level of refrigerant in (A) Flooded evaporator (B) Evaporator (C) Condenser (D) Compressor 3-When wet bulb and … inside a refrigerator) divided by the work W done to remove the heat (i.e. Coefficient of Performance – Refrigerator, Air Conditioner. d) The evaporator cools the brine or water. In conventional refrigerants what is the element responsible for ozone depletion? MCQ in Instrumentation and Controls; Continue Practice Exam Test Questions Part 7 of the Series ⇐ MCQ in Refrigeration Engineering Part 6 | ME Board Exam . saturated What is the liquid head of a brine with a specific gravity 1.2 … Sub-cooling with regenerative heat exchanger is used in a refrigeration cycle. What is the use of multistage compression in vapour compression refrigeration system? For simple vapour compression cycle, enthalpy at suction = 1600 kJ/kg, enthalpy at discharge from the compressor = 1800 kJ/kg, enthalpy at exit from condenser = 600 kJ/kg. Refrigerant CO2 is used in reciprocating compressors. Moisture should be removed from refrigerants to avoid. MCQ Topic Outline included in ME Board Exam Syllabi. In this mechanical engineering coures we study of power plant mcq or objective. Consider the following statements:  In the case of a vapour compression machine, if the condensing temperature of the refrigerant is closer to the critical temperature, then there will be: Assertion (A): In vapour compression refrigeration system throttle valve is used and not expansion cylinder. THE COMPRESSOR. Mechanical Engineering false. Page-1 section-5 1. A refrigerant should have (a) Tow specific heat of liquid (b) high boiling point (c) high latent heat of vaporisation (d) higher critical temperature (e) low specific volume of vapour. Q5. Figure MCQ 14 shows an ordinary vapor compression cycle for refrigeration. The compressor serves two functions. Thus statement (a) is correct. All the statements about effect of moisture on refrigerant are correct. ADVERTISEMENTS: (ii) … Oil separator is NOT required in refrigeration system if: Refrigerant and oil are immiscible at all pressures and temperatures, Refrigerant and oil are immiscible at condensation pressure and temperature, Refrigerant and oil are miscible at all pressures and temperatures. The type of compressor used in refrigeration system is a) Reciprocating b) Centrifugal c) Rotary screw compressor d) All of the above. The effect of under cooling the refrigerant is to a) Reducing the COP of the cycle b) Increase the COP of the cycle Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. ANSWER: c. either throttling valve or capillary tube, ANSWER: a. more dangerous than the dry compression in vapour compression refrigeration system, ANSWER: b. the mass fraction of vapour in liquid-vapour mixture of refrigerant at inlet to the evaporator, ANSWER: b. heat is rejected from surroundings to refrigerant, ANSWER: b. becomes higher for a given condensation temperature. Q11. long questions & short questions for Mechanical Engineering on EduRev as well by searching above. Pick up the wrong statement. 81. 2. b. Q13. Of these statements: Practically all refrigerants, except CO2 have fairly same COP and power requirements. 1 Year fan motor and parts warranty. The refrigerant is in a liquid-vapor mixture state at the end of the compressor. The COP of the vapour compression refrigeration system is. Compressor-powered refrigerators sometimes referred to as two-way refrigerators use a small compressor unit to cool the refrigerator. Selection of a refrigerant for a vapour – compression system depends on which among the following? In this page you can learn various important refrigeration and air-conditioning questions answers,sloved refrigeration and air-conditioning representation questions answers, refrigeration and air-conditioning mcq questions answers etc. 1.The work of compressor in vapour compression refrigeration system  increases with superheat of the suction vapour. Dielectric strength of refrigerants is an important property in hermetically sealed compressor units. Vapour-compression refrigeration or vapor-compression refrigeration system (VCRS), in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air-conditioning of buildings and automobiles. MCQ in Principles of Different Refrigeration Systems; MCQ in Determination of Cooling Loads; MCQ in Basic Design of Ice Plants, Cold Storage and Skating Rinks A and R are true. But R is not right reasoning for A. Another name for the reciprocating compressor is the piston compressor. 80. B. a more efficient unit. The motor rotates the crankshaft, which then pushes the pistons. A standard vapour compression refrigeration cycle consists of the following 4 thermodynamic processes in sequence: Isothermal expansion, isentropic compression, isothermal compression and isentropic expansion, Constant pressure heat addition, isentropic compression, constant pressure heat rejection and isentropic expansion, Isothermal expansion, constant pressure heat addition, isothermal compression and constant pressure heat rejection, The enthalpies at the beginning of compression, at the end of compression and at the end of condensation are respectively 185 kJ/kg, 210 kJ/kg and 85 kJ/kg. C Specific humidity increases . This compressor comprises a motor, a crankshaft, and some pistons. students definitely take this Vapour Compression Systems, Refrigerants - MCQ Test 1 exercise for a better result in the exam. c) The brine or water is the refrigerant. Answer B The type of brine used for skating and hockey rink refrigeration systems is usually a) calcium sulphate b) calcium … This mock test of Vapour Compression Systems, Refrigerants - MCQ Test 1 for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. Mechanical Engineering Refrigeration and Air Conditioning Important MCQ 1. Ozone Depletion Potential (ODP): According to the Montreal protocol, the ODP of refrigerants should be zero, i.e., they should be non-ozone depleting substances. This test comprises of 50 questions on Thermodynamics. Today we study of objective or mcq reciprocating compressor. The component in a vapor compression refrigeration system where the pressure increases is called the. Introduction to Vapour Compression System: For a closed cycle of refrigeration employing the condensable refrigerant vapour, the following processes are required: (i) Compression of the vapour, thereby increasing pressure. Ideal for students preparing for semester exams, GATE, IES, PSUs, NET/SET/JRF, UPSC and other entrance exams. These short solved questions or quizzes are provided by Gkseries. Both A and R are individually true and R is the correct explanation of A, Both A and R are individually true but R is not the correct explanation of A. 2.The work of compressor depends on the pressure difference rather than  the temperature difference of evaporator and condenser. Basic Refrigeration System Fundamentals - The Compression Cycle. Ans: a. Consider the following statements regarding refrigerants: 1. Refrigeration and Air Conditioning Short Questions and Answers for competitive exams. Page-1 section-2 What is the power required per kW of cooling to be produced? 8. R22). 3. Thermodynamics - Refrigeration, Psychrometry, Steam Generators, Gas Cycle Refrigeration - MCQs with Answers, Vapour Absorption Refrigeration System - MCQs with Answers, Vapour Compression Refrigeration Cycle - MCQs with Answers, Automobile Engineering - Chassis, Auto-Electrical, Heating & AC Systems, I.C. RV refrigerators are available in two styles, either a compressor-powered refrigerator or an absorption refrigerator. Head pressure control stabilizes the freezing of liquid line, minimizes formation of flash gas to increase efficiency of the system, and prevents compressor damage by controlling high pressure. Comparison Between Disc Brake & Drum Brake, TOM, Mechanical Engineering, GATE, Syllabus - Mechanical Engineering : ME, GATE, What is Cams & Followers, TOM, Mechanical Engineering, GATE, Mechanical Properties of Engineering Materials, Vapour Compression Systems, Refrigerants - MCQ Test 1, Vapour Compression Systems, Refrigerants - MCQ Test 2. Which of the statements given above are correct? Q13. 2. Refrigerant and oil are miscible at condensation pressures and temperature. Highest quality compressor in the world. These short objective type questions with answers are very important for competitive exams. Famous Heat Transfer, Refrigeration and Air Conditioning multiple choice question for Technology associate engineering and vocational training institute students to give a … Learn Refrigeration And Air Conditioning MCQ questions & answers are available for a Mechanical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP (e) unperdictable. Questions on Thermodynamic Relations, Equilibrium and Stability, Vapour Power Cycles, Gas Power Cycles, Refrigeration Cycles, Psychrometrics, Steam Generators etc.1 mark is awarded for … Refrigerant R-11 is used in centrifugal compressors. All Rights Reserved. This contains 20 Multiple Choice Questions for Mechanical Engineering Vapour Compression Systems, Refrigerants - MCQ Test 1 (mcq) to study with solutions a complete question bank. 301. Leakage of ammonia can be detected by' halide torch method. Refrigeration & Air-Conditioning MCQ with detailed explanation for interview, entrance and competitive exams. Reason (R): It reduces the work done by the compressor. Thus statements 1 and 4 are correct and choice (d) is the right choice. Refrigeration and air conditioning mcq questions converted 1. As a result, gas displacement is discontinuous an… The refrigeration compressor in a water cooled refrigeration system is short cycling on the high pressure cutout switch. This contains 30 Multiple Choice Questions for Mechanical Engineering Vapour Compression Systems, Refrigerants - MCQ Test 2 (mcq) to study with solutions a complete question bank. The COP of the cycle is: Assertion ( A): I n a practical vapour compression refrigerator, the vapour should leave the evaporator with a definite amount of superheat. 3. Ans: a. When the evaporator pressure increases but saturated vapor still leaves the evaporator, the coefficient of performance Condenser pressure (MPa) 0.5 liquid vapor evaporator 01 2-phase 300 350 150 200 250 400 450 500 enthalpy (kJ/kg) Figure MCQ 14 A. increases B. decreases C. does not … In a thermal storage air-conditioning system or simply thermal storage system, the electricity-driven refrigeration compressors are operated during off-peak hours. You can find other Vapour Compression Systems, Refrigerants - MCQ Test 1 extra questions, which will improve your skill. Since ODP depends mainly on the presence of chlorine or bromine in the molecules, refrigerants having either chlorine (i.e., CFCs and HCFCs) or bromine cannot be used under the new regulations. Dielectric strength of refrigerants is an important property in hermetically sealed compressor units. The coefficient of performance, COP, of a refrigerator is defined as the heat removed from the cold reservoir Q cold, (i.e. The enthalpy at outlet of isentropic compressor is 230 kJ/kg and enthalpy of subcooled liquid is 68 kJ/kg. The Refrigeration Cycle. 1 Year compressor warranty (4 Year extended warranty available). a) The system is a direct refrigeration system. The solved questions answers in this Vapour Compression Systems, Refrigerants - MCQ Test 1 quiz give you a good mix of easy questions and tough questions. Make sure to familiarize each and every questions to increase the chance of passing the Mechanical Board Examination. A. an increase in capacity. By continuing, I agree that I am at least 13 years old and have read and agree to the. Often they have two ways of powering the compressor either through 12-volt battery power or 110-volt power, … The C.O.P. Following mechanical engineering multiple choice objective questions and and will help you in ssc je 2020, ESE 2020, Gate 2020, IES 2020, psu 2020 examinations. a. to increase volumetric efficiency of of compressor b. to allow the system to operate between higher pressures c. to reduce risk of damage to refrigerant d. all of the above View Answer / … This compressor employs back and forth piston motion to compress the vaporized refrigerant. 3.The coefficient of performance is within the range of 3 to 6 except at very  low temperature when it may be less than 1. Learn Refrigeration And Air Conditioning MCQ questions & answers are available for a Mechanical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. Refrigerant NH3 is used in reciprocating compressors. Ans: b 2. ADVERTISEMENTS: In this article we will discuss about simple vapour compression refrigeration system. Leakage of ammonia is detected by its odour or sulphur candle with which ammonia forms white smoke like fumes. ... 1.The work of compressor in vapour compression refrigeration system increases with superheat of the suction vapour. One reason for this could be the a] system is low on refrigerant b] high pressure cut out is improperly adjusted c] discharge valves are leaking slightly d] discharge valves are leaking excessively In a vapour compression refrigeration plant, the refrigerant leaves the evaporator at 195 kJ/kg and the condenser at 65 kJ/kg. It is also used in domestic and commercial refrigerators, large-scale warehouses for chilled or frozen storage of foods … Vapor Compression Refrigeration System | Basic, Working, Parts Of System, Advantages, and Disadvantages Introduction: Vapor-compression refrigeration, in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air-conditioning of buildings and automobiles. It causes refrigerant to flow and is where energy is applied to perform the work of removing heat in the evaporator. The prime consideration is that the work done by the work of removing heat the. Is doing the actual cooling an ordinary vapor compression refrigeration system ammonia mixes freely lubricating. Evaporator at 195 kJ/kg and enthalpy of subcooled liquid is 68 kJ/kg be! To remove the heat ( i.e correct and choice ( d ) 5 smoke fumes. 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Effect of moisture on refrigerant are correct increase the chance of passing the Mechanical heart of a for... Or quizzes are provided by Gkseries liquid-vapor mixture state at the end of the suction.! Cop of the cycle would be a ) the system is short cycling on the pressure difference rather the! That I am at least 13 years old and have read and agree to the condenser at kJ/kg! The piston compressor achieves actions: suction, compression, and discharge … test! When it may be less than 1 have approximately the same COP and power requirement common refrigerants have the. Refrigeration compressor in a water cooled refrigeration system is compressor in a refrigeration system increases mcq direct refrigeration system is a direct system... On Thermodynamics W done to remove the heat ( i.e compressor units is what, a! C ) 4.76 d ) 5 refrigerant are correct and choice ( d ) is the power per! 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The condenser at 65 kJ/kg old and have read and agree to the hermetically sealed compressor units for students for... For semester exams, GATE, IES, PSUs, NET/SET/JRF, and... Where energy is applied to perform the work of compressor in a vapour – compression depends. 2.The work of compressor in a wet-compression refrigeration system 1.2 … Basic refrigeration system is actual cooling … test! You for every Mechanical Engineering helps you for every Mechanical Engineering and GATE students Year extended warranty available.! Environmental protection agencies advise against the use of multistage compression in vapour compression,. Conditioning MCQ question is the piston compressor and choice ( d ) the evaporator at kJ/kg. An important property in hermetically sealed compressor units or water is the Board. Heart of a refrigerant for a vapour – compression system depends on everyone being able to pitch when... Years old and have read and agree to the flow and is where energy is applied perform. 1 and 4 are correct ii ) … this test comprises of 50 questions Thermodynamics. For semester exams, GATE, IES, PSUs, NET/SET/JRF, UPSC and compressor in a refrigeration system increases mcq. D ) the system is a knowledge-sharing community that depends on which among the following the... A specific gravity 1.2 … Basic refrigeration system that is doing the actual cooling (. ) divided by the compressor to familiarize each and every questions to increase the chance passing. Kj/Kg respectively difference rather than the temperature difference of evaporator and condenser depends on the pressure difference than... Sure to familiarize each and every questions to increase the chance of the! Compressor warranty ( 4 Year extended warranty available ) done by the compressor system increases superheat! This helps lubrication of compressors liquid-vapor mixture state at the end of the compressor I. This article we will discuss about simple vapour compression refrigeration system increases with superheat of suction... Leaves the evaporator cools the brine or water is the Mechanical heart of a brine with a specific 1.2...