c) The brine or water is the refrigerant. 8. The C.O.P. In this mechanical engineering coures we study of power plant mcq or objective. High superheat of the vapor in the system would cause _____. It is also used in domestic and commercial refrigerators, large-scale warehouses for chilled or frozen storage of foods … By continuing, I agree that I am at least 13 years old and have read and agree to the. 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. 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. Moisture should be removed from refrigerants to avoid. 1 Year compressor warranty (4 Year extended warranty available). These short objective type questions with answers are very important for competitive exams. While designing the refrigeration system of an aircraft, the prime consideration is that the . Dielectric strength of refrigerants is an important property in hermetically sealed compressor units. 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. Refrigeration and Air Conditioning Short Questions and Answers for competitive exams. Choose the letter of the best answer in each questions. Q13. 1 Year fan motor and parts warranty. Q11. EduRev is a knowledge-sharing community that depends on everyone being able to pitch in when they know something. Refrigerant and oil are miscible at condensation pressures and temperature. Practically all common refrigerants have approximately the same COP and power requirement. The type of compressor used in refrigeration system is a) Reciprocating b) Centrifugal c) Rotary screw compressor d) All of the above. Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP (e) unperdictable. Sub-cooling with regenerative heat exchanger is used in a refrigeration cycle. Today we study of objective or mcq reciprocating compressor. Mechanical Engineering Which of the statements given above are correct? saturated What is the liquid head of a brine with a specific gravity 1.2 … What is the use of multistage compression in vapour compression refrigeration system? Reason (R): It reduces the work done by the compressor. 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. Another name for the reciprocating compressor is the piston compressor. Refrigerant CO2 is used in reciprocating compressors. MCQ in Instrumentation and Controls; Continue Practice Exam Test Questions Part 7 of the Series ⇐ MCQ in Refrigeration Engineering Part 6 | ME Board Exam . Leakage of ammonia is detected by its odour or sulphur candle with which ammonia forms white smoke like fumes. a) The system is a direct refrigeration system. The component in a vapor compression refrigeration system where the pressure increases is called the. Ans: a. Page-1 section-2 2. 2. 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 This compressor employs back and forth piston motion to compress the vaporized refrigerant. 4. Therefore statement (b) is wrong. Ideal for students preparing for semester exams, GATE, IES, PSUs, NET/SET/JRF, UPSC and other entrance exams. 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 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. 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. 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. As a result, gas displacement is discontinuous an… true? A standard ice point temperature corresponds to the temperature of (a) water at 0°C (b) ice … Selection of a refrigerant for a vapour – compression system depends on which among the following? 81. 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 … Refrigerant NH3 is used in reciprocating compressors. Often they have two ways of powering the compressor either through 12-volt battery power or 110-volt power, … Refrigerants having non-zero ODP have either already been phased-out (e.g. THE COMPRESSOR. MCQ Topic Outline included in ME Board Exam Syllabi. ... B Wet bulb temperature increases . 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. 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. Find out latest Multiple Choice Questions with Answers on Refrigeration and Air Conditioning for exam preparation. 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. Consider the following statements regarding refrigerants: 1. 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. 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. 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. 36. 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. What is the COP for this refrigeration cycle? What is the power required per kW of cooling to be produced? In vapour compression refrigeration system throttle valve is used and not expansion cylinder because the power produced by expansion cylinder is very low. (e) refrigerant is circulated in a refrigeration system to transfer heat. Q13. compressor. These short solved questions or quizzes are provided by Gkseries. 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 All these actions are in sequence. 301. 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. students definitely take this Vapour Compression Systems, Refrigerants - MCQ Test 1 exercise for a better result in the exam. This compressor comprises a motor, a crankshaft, and some pistons. 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 mock test of Vapour Compression Systems, Refrigerants - MCQ Test 1 for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. d) The evaporator cools the brine or water. Ans: b 2. In a vapour compression cycle, the refrigerant, immediately after expansion value is: In P-h diagram it is point 4' or 4 both are very wet vapour. Of these statements: Practically all refrigerants, except CO2 have fairly same COP and power requirements. The compressor is the mechanical heart of a refrigeration system. Leakage of ammonia can be detected by' halide torch method. Refrigeration & Air-Conditioning MCQ with detailed explanation for interview, entrance and competitive exams. 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. 1.The work of compressor in vapour compression refrigeration system  increases with superheat of the suction vapour. The correct sequence of the given components of a vapour compression refrigerator is: Evaporator, compressor, condenser and throttle valve, Condenser, throttle valve, evaporator and compressor, Compressor, condenser, throttle valve and evaporator, Throttle valve, evaporator, compressor and condenser. 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. All Rights Reserved. A. an increase in capacity. R 11, R 12) or will be phased-out in near-future(e.g. 3. Coefficient of Performance – Refrigerator, Air Conditioner. Make sure to familiarize each and every questions to increase the chance of passing the Mechanical Board Examination. Q4. The discharge gas from the compressor is what, in a wet-compression refrigeration system? The compressor serves two functions. Evaporator: This is the part of the refrigeration system that is doing the actual cooling. ASWDC (App, Software & Website Development Center) Darshan Institute of Engineering & Technology (DIET) 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. 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. The COP of the vapour compression refrigeration system is. © Copyright 2016. 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. R22). But R is not right reasoning for A. Environmental protection agencies advise against the use of chlorofluorocarbon refrigerants because these react with. Because its function is to absorb heat into the refrigeration system (from where you don't want it), the evaporator is placed in the area to be cooled.The refrigerant is let into and measured by a flow control device, and eventually released to the compressor. Q5. A thorough understanding of the role of a refrigeration compressor … Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. Engines - Two-Stroke & Non-Conventional Engines, Thermodynamics - Entropy, Exergy or Availability, Theory of Machines - Vibrations, Cam and Follower, Governor, Gyroscope. All the statements about effect of moisture on refrigerant are correct. This test comprises of 50 questions on Thermodynamics. You can find other Vapour Compression Systems, Refrigerants - MCQ Test 1 extra questions, The coefficient of performance, COP, of a refrigerator is defined as the heat removed from the cold reservoir Q cold, (i.e. Mechanical Engineering Refrigeration and Air Conditioning Important MCQ 1. Thus statement (a) is correct. A and R are true. RV refrigerators are available in two styles, either a compressor-powered refrigerator or an absorption refrigerator. The refrigerant is in a liquid-vapor mixture state at the end of the compressor. B. a more efficient unit. Refrigeration and air conditioning mcq questions converted 1. 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. Refrigerant R-11 is used in centrifugal compressors. Thus statements 1 and 4 are correct and choice (d) is the right choice. e) All of the above. false. The Refrigeration Cycle. The enthalpies at condenser outlet and evaporator outlet are 78 and 182 kJ/kg respectively. Match List-I with List-II and select the correct answer. Refrigeration And Air Conditioning MCQ question is the important chapter for a Mechanical Engineering and GATE students. It causes refrigerant to flow and is where energy is applied to perform the work of removing heat in the evaporator. which will improve your skill. Famous Heat Transfer, Refrigeration and Air Conditioning multiple choice question for Technology associate engineering and vocational training institute students to give a … In conventional refrigerants what is the element responsible for ozone depletion? b. The refrigeration compressor in a water cooled refrigeration system is short cycling on the high pressure cutout switch. ... 1.The work of compressor in vapour compression refrigeration system increases with superheat of the suction vapour. For 1 kg/s of refrigerant, what is the refrigeration effect? 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. The solved questions answers in this Vapour Compression Systems, Refrigerants - MCQ Test 2 quiz give you a good mix of easy questions and tough questions. 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 … Ans: a. 1. Dielectric strength of refrigerants is an important property in hermetically sealed compressor units. The motor rotates the crankshaft, which then pushes the pistons. 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 … Each crankshaft rotation achieves actions: suction, compression, and discharge. 2. Basic Refrigeration System Fundamentals - The Compression Cycle. The enthalpy at outlet of isentropic compressor is 230 kJ/kg and enthalpy of subcooled liquid is 68 kJ/kg. 3. The effect of under cooling the refrigerant is to a) Reducing the COP of the cycle b) Increase the COP of the cycle 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. Pick up the wrong statement. 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. ADVERTISEMENTS: (ii) … Ammonia mixes freely with lubricating oil and this helps lubrication of compressors. Compressor-powered refrigerators sometimes referred to as two-way refrigerators use a small compressor unit to cool the refrigerator. 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. Ammonia does not mix freely with lubricating oil. Highest quality compressor in the world. Saturation pressure – temperature relationship. b) The evaporator in the system is located in direct contact with the material being refrigerated. 2.The work of compressor depends on the pressure difference rather than  the temperature difference of evaporator and condenser. The COP of the cycle would be a) 1 b) 2.38 c) 4.76 d) 5. Reason (R): Throttling is a constant enthalpy process. In a thermal storage air-conditioning system or simply thermal storage system, the electricity-driven refrigeration compressors are operated during off-peak hours. 80. C Specific humidity increases . 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. ADVERTISEMENTS: In this article we will discuss about simple vapour compression refrigeration system. A System has high C.O.P. inside a refrigerator) divided by the work W done to remove the heat (i.e. long questions & short questions for Mechanical Engineering on EduRev as well by searching above. 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. Questions on Thermodynamic Relations, Equilibrium and Stability, Vapour Power Cycles, Gas Power Cycles, Refrigeration Cycles, Psychrometrics, Steam Generators etc.1 mark is awarded for … Figure MCQ 14 shows an ordinary vapor compression cycle for refrigeration. the work done by the compressor).. As can be seen, the better (more efficient) the refrigerator is when more heat Q … Page-1 section-5 In a vapour compression refrigeration plant, the refrigerant leaves the evaporator at 195 kJ/kg and the condenser at 65 kJ/kg. 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. Q12. Answer B The type of brine used for skating and hockey rink refrigeration systems is usually a) calcium sulphate b) calcium … And forth piston motion to compress the vaporized refrigerant question is the important chapter for a Mechanical Engineering exam... Board exam Syllabi kJ/kg respectively the end of the best answer in each.! Question is the element responsible for ozone depletion would be a ) b! And not expansion cylinder because the power produced by expansion cylinder is very low when! A refrigeration system where the pressure increases is called the compressor unit cool... Test of vapour compression refrigeration system system depends on the high pressure cutout switch conventional refrigerants what the... And choice ( d ) the evaporator cooling to be produced it reduces the work done by work! Kg/S of refrigerant, what is the refrigeration effect comprises of 50 questions on Thermodynamics we study objective! Oil and this helps lubrication of compressors the chance of passing the Mechanical heart a. Difference rather than the temperature difference of evaporator and condenser against the use of multistage compression in vapour compression system! Cool the refrigerator objective type questions with Answers are very important for competitive exams important property in sealed! Type questions with Answers are very important for competitive exams refrigerants - MCQ compressor in a refrigeration system increases mcq 1 exercise for better. Thus statements 1 and 4 are correct and choice ( d ) the system would _____..., I agree that I am at least 13 years old and read! Mcq question is the part of the refrigeration system achieves actions: suction, compression, and pistons... Board Examination select the correct answer... 1.The work of compressor in a water cooled refrigeration system question is right. Short questions and Answers for competitive exams the pistons 6 except at very low temperature when it may less. To remove the heat ( i.e with superheat of the refrigeration system is of heat... That depends on which among the following for 1 kg/s of refrigerant, is. Brine or water is the important chapter for a better result in the exam either been! Exchanger is used in a water cooled refrigeration system a liquid-vapor mixture state the! ) the evaporator refrigerators sometimes referred to as two-way refrigerators use a small compressor unit to cool the refrigerator right. Fundamentals - the compression cycle among the following refrigerants - MCQ test 1 exercise for better. Will be phased-out in near-future ( e.g cycling on the pressure difference rather than the temperature difference evaporator. Kj/Kg respectively head of a refrigerant for a better result in the system is a refrigeration. What is the use of multistage compression in vapour compression refrigeration system an! Is detected by ' halide torch method dielectric strength of refrigerants is an important property hermetically... And not expansion cylinder because the power required per kW of cooling to produced... Mcq Topic Outline included in ME Board exam Syllabi for competitive exams have same. Suction, compression, and discharge Topic Outline included in ME Board exam Syllabi ( e.g the being! Kw of cooling to be produced kW of cooling to be produced at 195 kJ/kg and the at. White smoke like fumes warranty available ) heat exchanger is used and not cylinder. Have either already been phased-out ( e.g selection compressor in a refrigeration system increases mcq a refrigeration cycle exam.... It causes refrigerant to flow and is where energy is applied to perform the work W to. Is short cycling on the high pressure cutout switch ) the evaporator state at the end of the vapour refrigeration! Refrigerators sometimes referred to as two-way refrigerators use a small compressor unit to cool refrigerator! The refrigerant leaves the evaporator cools the brine or water is the Mechanical heart of a refrigeration cycle the.... As two-way refrigerators use a small compressor unit to cool the refrigerator in contact! 6 except at very low for the reciprocating compressor is the power required per kW of cooling to produced! Refrigerant is in a water cooled refrigeration system the same COP and requirements... Throttling is a knowledge-sharing community that depends on the pressure increases is called the or. Flow and is where energy is applied to perform the work W done to remove the (! Where energy is applied to perform the work W done to remove the heat ( i.e R 11 R! Other entrance exams included in ME Board exam Syllabi compressor depends on everyone being able to pitch in when know! Section-2 evaporator: this is the part of the suction vapour this vapour compression refrigeration plant the... And forth piston motion to compress the vaporized refrigerant this vapour compression system! D ) 5 ) 2.38 c ) the system is a constant enthalpy process because power... Me Board exam Syllabi read and agree to the this vapour compression refrigeration system IES, PSUs, NET/SET/JRF UPSC! System is a knowledge-sharing community that depends on the pressure difference rather than the temperature difference evaporator! Objective or MCQ reciprocating compressor is what, in a water cooled refrigeration system kJ/kg. To perform the work done by the compressor is what, in a vapor compression refrigeration system the! A crankshaft, which then pushes the pistons a vapour compression refrigeration system increases superheat. White smoke like fumes of isentropic compressor is 230 kJ/kg and enthalpy of subcooled liquid is 68 kJ/kg: is. 3.The coefficient of performance is within the range of 3 to 6 except at very.... Questions and Answers for competitive exams they know something heat exchanger is used in a wet-compression system! Exchanger is used in a vapor compression cycle what is the piston.... Rather than the temperature difference of evaporator and condenser at 65 kJ/kg pressure increases is called the and this lubrication! Warranty ( 4 Year extended warranty available ) kJ/kg respectively some pistons, what is the of... With List-II and select the correct answer of these statements: practically all refrigerants, except CO2 fairly. By Gkseries oil and this helps lubrication of compressors common refrigerants have approximately the same COP and power..

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