Description : One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at ... ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions
Last Answer : Ans: c
Description : One ton of refrigeration is equal to the refrigeration effect corresponding to melting of 1000 kg of ice (a) in 1 hour (b) in 1 minute (c) in 24 hours (d) in 12 hours
Description : The general rule for rating refrigeration systems (excepting for CO2 system) is to approximate following h.p. per ton of Refrigeration (a) 0.1 to 0.5 h.p. per ton of refrigeration (b) 0.5 to 0.8 h.p. per ... (c) 1 to 2 h.p. per ton of refrigeration (d) 2 to 5 h.p. per ton of refrigeration
Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.
Last Answer : Ans: d
Description : One ton of refrigeration is not equivalent to the heat removal rate of (A) 200 BTU/minute (B) 50 kcal/minute (C) 50 kJ/sec (D) 3.5 KW
Last Answer : (C) 50 kJ/sec
Description : An engine produces 10 kW brake power while working with a brake thermal efficiency of 30%. If the calorific value of the fuel used is 40000 kJ/kg, then what is the fuel consumption? (a) 1.5 kg/hour (b) 3 kg/hour (c) 0.3 kg/hour (d) 1 kg/hour
Last Answer : Ans :b
Description : An engine working on air standard Otto cycle has a cylinder diameter of 10 cm and stroke length of 15 cm. The ratio of specific heats for air is 1.4. If the clearance volume is 196.3 cc and the heat supplied per kg of air per ... kg of air is a. 879.1 kJ/ b. 890.2 kJ c. 895.3 kJ d. 973.5 kJ
Last Answer : ANSWER d. 973.5 kJ
Description : Rating of a domestic refrigerator is of the order of (a) 0.1 ton (b) 5 tons (c) 10 tons (d) 40 tons
Last Answer : Ans: a
Description : In a constant pressure process steam is generated from 10 bar and 0.8 dry condition till it become dry and saturated. Determine amount of heat added per kg of steam. From steam table at 10 bar Tsat = 179.9°C hf = 762.6 kl/kg, hg = 2776.2 kJ/kg
Last Answer : Constant pressure process Final condition of steam is dry saturated Enthalpy of dry steam = hg= hf + hfg =2776.2 KJ/Kg .Given Latent heat of vaporization = hfg = hg - hf =2776.2-762.6 =2013.6 KJ/Kg Initial condition ... hfg = 762.6+0.8 X 2013.6 =2373.48 KJ/Kg Heat added = hg-hw = 402.72 KJ/kg
Description : In a boiler enthalpy of water supplied was 2000 kJ/kg. Enthalpy being added by fuel combustion is 3200 kJ/kg. Using first law of thermodynamics, find amount of heat supplied if steam generation rate is 10 tons per hour.
Last Answer : Heat supplied Q = m (h2-h1) …….(Steady flow energy equation for boiler) ; h2=3200 KJ/kg h1=2000 KJ/kg m = 10 Tons /hour = (10 x 1000)/3600 kg/sec = 2.77 Kg/sec Q = 2.77(3200-2000) = 3324 KJ/sec heat supplied for 10 Tons/hr steam generation
Description : A refrigeration cycle operates between condenser temperature of + 27°C and evaporator temperature of- 23°C. TheCarnot coefficient of performance of cycle will be (a) 0.2 (b) 1.2 (c) 5 (d) 6
Description : In a refrigeration cycle, the super heating……..C.O.P (a)decreases (b)does not change (c) increases (d)none of the above
Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers
Last Answer : Ans: b
Description : The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P. (a) more (b) less (c) equally. (d) unpredictable
Description : The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperatureconstant, will (a) increase (b) decrease (c) may increase or decrease depending on the type of refrigerant used (d) remain unaffected
Description : The refrigeration effect in a dry evaporator compared to flooded evaporator in a similar plant is (a) same (b) more (c) less (d) more or less depending on ambient conditions
Description : Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator
Description : The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used
Description : Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP
Description : Moisture in freon refrigeration system causes (a) ineffective refrigeration (b) high power consumption (c) freezing automatic regulating valve (d) corrosion of whole system
Description : For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphereis high, then (a) bigger cabinet should be used (b) smaller cabinet should ... tight vapour seal should be used (d) refrigerant with lower evaporation temperature should be used
Description : Superheating in a refrigeration cycle (a) increases COP (b) decreases COP (c) COP remains unaltered (d) other factors decide COP
Description : Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the orderof (a) 1 : 1 (b) 1 : 9 (c) 9 : 1 (d) 1 : 3
Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid
Description : The leaks in a refrigeration system using Freon are detected by (a) halide torch which on detection produces greenish flame lighting (b) sulphur sticks which on detection gives white smoke (c) using reagents (d) sensing reduction in pressure.
Description : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve
Description : Aqua ammonia is used as refrigerant in the following type of refrigeration system (a) compression (b) direct (c) indirect (d) absorption
Description : Highest pressure encountered in a refrigeration system should be (a) critical pressure of refrigerant (b) much below critical pressure (c) much above critical pressure (d) near critical pressure
Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser
Description : In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect
Description : In a refrigeration system, heat absorbed in comparison to heat rejected is (a) more (b) less (c) less for small capacity and more for high capacity. (d) more for small capacity and less for high capacity
Description : Highest temperature encountered in refrigeration cycle should be (a) near critical temperature of refrigerant (b) above critical temperature (c) atcritica. temperature (d) much below critical temperature
Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction
Description : Air refrigeration operates on (a) Carnot cycle (b) Reversed Carnot cycle (c) Rankine cycle (d) Brayton cycle.
Description : Refrigeration in aeroplanes usually employs the following refrigerant (a) Co2 (b) Freon-11 (c) Freon-22 (d) Air
Description : An important characteristic of absorption system of refrigeration is (a) noisy operation (b) quiet operation (c) very little power consumption (d) its input only in the form of heating.
Last Answer : Ans: D
Description : Ammonia-absorption refrigeration cycle requires (a) very little work input (b) maximum work input (c) nearly same work input as for vapour compression cycle (d) zero work input
Description : Vapour compression refrigeration is some what like (a) Carnot cycle (b) Rankine cycle (c) reversedCamot cycle (d) reversed Rankine cycle
Last Answer : Ans: C
Description : Pick out the wrong statement. (A) A refrigeration cycle violates the second law of thermodynamics (B) Refrigeration cycle is normally represented by a temperature vs. entropy plot (C) In a refrigerator, ... (D) One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW
Last Answer : (A) A refrigeration cycle violates the second law of thermodynamics
Description : One tonrefrigeration corresponds to (a) 50 kcal/min (b) 50 kcal/kr (c) 80 kcal/min (d) 80 kcal/hr
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 : The unit of calorific value of fuel is __________ . a) Kj /Kg b) J/Kg c)Kj /g d)J/g
Last Answer : a) Kj /Kg
Description : One ton of refrigeration capacity is equivalent to the heat removal rate of (A) 50 kcal/hr (B) 200 BTU/hr (C) 200 BTU/minute
Last Answer : (C) 200 BTU/minute
Description : The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiller
Last Answer : kW/Ton of Refrigeration
Description : The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiLLER
Description : Which one is not an energy consumption benchmark parameter? a) kcal/kWh of electricity generated b) kg/ oC. c) kW/ton of refrigeration d) kWh/kg of yarn
Last Answer : b) kg/ oC.
Description : The benchmarking parameter for a vapour compression refrigeration system is a) kW / kg of refrigerant used b) kcal / m3 of chilled water c) BTU / Ton of Refrigeration d) kW / Ton of Refrigeration
Last Answer : d) kW / Ton of Refrigeration
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.
Last Answer : 1 ton of refrigeration is 12000 BTU.
Description : The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is (a) bigger (b) smaller (c) equal (d) smaller/bigger depending on capacity