Description : The C.O.P. of a domestic refrigerator in comparison to domestic air conditioner will be (a) same (b) more (c) less (d) dependent on weather conditions
Last Answer : Ans: c
Description : Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)? (A) Air cycle (B) Carnot cycle (C) Ordinary vapour compression cycle (D) Vapour compression with a reversible expansion engine
Last Answer : A) Air cycle
Description : The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a ... )R = 1.5; (COP)HP = 2.5 (D) (COP)R = (COP)HP = 2.5
Last Answer : (C) (COP)R = 1.5; (COP)HP = 2.5
Description : Co-efficient of Performance (COP) of a refrigerator is the ratio of the (A) Work required to refrigeration obtained (B) Refrigeration obtained to the work required (C) Lower to higher temperature (D) Higher to lower temperature
Last Answer : (B) Refrigeration obtained to the work required
Description : Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is (A) 3 (B) 5 (C) 0.5 (D) 1.5
Last Answer : Option A
Description : The COP of a domestic refrigerator (a) is less than 1 (b) is more than 1 (c) is equal to 1 (d)depends upon the weather conditions.
Last Answer : Ans: b
Description : The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same. (A) Kinematic viscosity (B) Work (C) Temperature (D) None of these
Last Answer : (D) None of these
Description : Domestic refrigerator usually works on the __________ refrigeration cycle. (A) Carnot (B) Air (C) Absorption (D) vapour-ejection
Last Answer : (C) Absorption
Description : A refrigerator is working on reversed carnot cycle between temperature of 30°C to –10°C with capacity of 10 tonnes. Calculate. (i) The COP (ii) Define ton of refrigeration (iii) Give the industrial application of refrigeration
Last Answer : (ii) Ton of refrigeration: It is defined as the quantity of heat required to be removed from 1Ton water at 0oC to get ice at 0oC in one day. (iii) Industrial applications of refrigeration ... food stuff such as meat, fruit, fruit juice, vegetables etc. 5. Ice cooling of concrete for dam.
Description : Capacity & power requirement for an air compressor working at high altitude compared to sea-level will be (A) More (B) Less (C) Same (D) Either more or less; depends on the climatic conditions
Last Answer : (B) Less
Description : Co-efficient of performance for a reversed Carnot cycle working between temperatures T1 and T2(T1 > T2) is (A) T2/(T1- T2) (B) T1/(T1- T2) (C) (T1- T2)/T1 (D) (T1- T2)/T2
Last Answer : (A) T2/(T1- T2)
Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/R1
Last Answer : (A) T1/(T1-T2)
Description : The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2(when, T1 > T2) is given by (T1- T2)/T1. The co efficient of performance (CO.P.) of a Carnot heat pump operating between T1 and T2is given by (A) T1/(T1-T2) (B) T2/(T1-T2) (C) T1/T2 (D) T2/T1
Last Answer : (B) T2/(T1-T2)
Description : Ideal refrigeration cycle is (A) Same as Carnot cycle (B) Same as reverse Carnot cycle (C) Dependent on the refrigerant's properties (D) The least efficient of all refrigeration processes
Last Answer : (B) Same as reverse Carnot cycle
Description : Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator
Last Answer : Ans: a
Description : Which of the following has the minimum value of COP for a given refrigeration effect? (A) Reverse Carnot cycle (B) Ordinary vapour-compression cycle (C) Vapour-compression process with a reversible expansion engine (D) Air refrigeration cycle
Last Answer : (D) Air refrigeration cycle
Description : Out of the following refrigeration cycles, which one has maximum COP? (A) Air cycle (B) Carnot cycle (C) Ordinary vapor compression cycle (D) Vapor compression with a reversible expansion engin
Last Answer : (B) Carnot cycle
Description : Pick out the wrong statement (A) Low ozone layer thickness in polar regions is due to cold climatic conditions (B) Amount of unburnt hydrocarbons emitted by two stroke petrol engine is more ... can enter the blood stream & the digestive system/ lungs and is responsible for causing Minamata disease
Last Answer : (D) Mercury as a pollutant can enter the blood stream & the digestive system/ lungs and is responsible for causing Minamata disease
Description : In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be (A) 5.2 (B) 6.2 (C) 0.168 (D) Data insufficient, can't be found out
Last Answer : A) 5.2
Description : If h1 = inner film co-efficient and /h2 = outer film co-efficient, then the overall heat transfer co-efficient is (A) Always less than h1 (B) Always between h1 and h2 (C) Always higher than h2 (D) Dependent on metal resistance
Last Answer : (B) Always between h1 and h2
Description : If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of - 23°C,then the Carnot COP will be (a) 0.2 (b) 1.2 (c) 5 (d) 6
Last Answer : Ans: d
Description : Efficiency of a Carnot engine is given as 80%. If the- cycle direction be reversed, what will be the value of COP ofreversed Carnot cycle (a) 1.25 (b) 0.8 (c) 0.5 (d) 0.25
Description : If both Stirling and Carnot cycles operate within the same temperature limits, then efficiency of Stirling cycle as compared to Carnot cycle (a) more (b) less (c) equal (d) depends on other factors (e) none of the above.
Last Answer : Answer : c
Description : The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is (A) Less pronounced (B) More pronounced (C) Equal (D) Data insufficient, can't be predicted
Last Answer : (B) More pronounced
Description : The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor
Last Answer : (C) Some
Description : COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about (A) 0.5 (B) 3.5 (C) 4.5 (D) 8.5
Last Answer : (B) 3.5
Description : In a working refrigerator, the value of COP is always (A) 0 (B) < 0 (C) < 1 (D) > 1
Last Answer : (D) > 1
Description : What is use of refrigerant gas in Air conditioner and in Refrigerator?
Last Answer : Refrigerants are the common name for the chemical blend that cycles through the AC, changing from liquid to a gas as it absorbs and release heat.
Description : A refrigerator may be termed as a (A) Heat pump (B) Heat engine (C) Carnot engine (D) None of these
Last Answer : (A) Heat pump
Description : What do you mean by domestic air conditioner?
Last Answer : Ans. It is a closed self conducted cooling unit in a cabinet. It is modular in nature. It works on the principle of Thermodynamics second law and works on refrigeration cycle.
Description : The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which ‘D’ is the diffusivity of solute, is (A) D/a (B) D/2a (C) Proportional to √D (D) Dependent on the Reynolds number
Last Answer : (D) Dependent on the Reynolds number
Description : Weight of 1 m3 of humid air as compared to 1 m3 of dry air, under the same conditions, is (A) Less (B) More (C) Same (D) Unpredictable
Last Answer : (A) Less
Description : A domestic refrigerator has a/an __________ cooled condenser. (A) Water (B) Air (C) Evaporative (D) Gas
Last Answer : (B) Air
Description : For better COP of refrigerator, the pressure range corresponding to temperature in evaporator and condenser must be (a) small (b) high (c) equal (d) anything
Description : What states that thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same and that no heat engine is more efficient than a reversible one operating between the ... A. Ericson principle B. Carnot principle C. Otto principle D. Stirling principle
Last Answer : Carnot principle
Description : The vapour compression refrigerator employs the following cycle (a) Rankine (b) Carnot (c) Reversed Carnot. (d) Brayton
Description : For aluminium, as compared to copper, all the following factors have higher values except (a) specific volume (6) electrical conductivity (c) co-efficient of linear expansion (d) resistance per unit length for same cross-section
Last Answer : (6) electrical conductivity
Description : Refrigeration capacity of a household refrigerator may be round about __________ tons. (A) 0.15 (B) 1.5 (C) 4.5 (D) 6.5
Last Answer : (A) 0.15
Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher
Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher
Description : India provides ideal conditions for air travel because (a) it is a vast country (b) it has a huge population (c) its climatic conditions are favourable (d) it has extensive mountain tracks
Last Answer : Ans: (c)
Description : The relative coefficient of performance is (a) actual COP/theoretical COP (b) theoretical COP/actual COP (c) actual COP x theoretical COP (d) 1-actual COP x theoretical COP
Description : Full form of COP is A. Coefficient of Pressure B. Coefficient of performance C. Coefficient of program D. None of the above
Last Answer : Coefficient of performance
Description : The coefficient of performance (COP) is the ratio between the: A. Power consumption in watts and heat absorbed per hour B. Heat absorbed per hour and the power consumption in watts C. Work required and the absorbed heat D. Absorbed heat and work required
Last Answer : Absorbed heat and work required
Description : Which one is the correct relation between energy efficiency ratio (EER) and coefficient of performance (COP)? A. EER = 2.34 COP B. EER = 3.24 COP C. EER = 3.42 COP D. EER = 4.23 COP
Last Answer : EER = 3.42 COP
Description : For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is (A) More (B) Less (C) Equal (D) Either (A) or (B); depends on the viscosity of the fluid
Last Answer : (A) More
Description : Testing of the knocking characteristics of petrofuels is done in a __________ engine. (A) Carnot (B) CFR (Co-operative fuel research) (C) Stirling (D) Diesel
Last Answer : (B) CFR (Co-operative fuel research)
Description : Which of the following engines is the most efficient? a. Gas turbine b. Diesel engine c. Carnot engine d. Gasoline engine
Last Answer : Carnot engine
Description : Which of the following is least efficient? a. Gas turbine b. Diesel engine c. Carnot engine d. Gasoline engine
Last Answer : Gasoline engine
Description : The most efficient cycle that can operate between two constant temperature reservoir is the _________. a. Otto Cycle b. Lazare Cycle c. Isothermal Cycle d. Carnot Cycle
Last Answer : Carnot Cycle
Description : What is a heat engine that operates on the reversible Carnot cycle called? A. Carnot heat engine B. Ideal heat engine C. Most efficient heat engine D. Best heat engine
Last Answer : Carnot heat engine