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