Description : The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is (A) Less (B) More (C) Same (D) Dependent on climatic conditions
Last Answer : (A) Less
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 formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption
Last Answer : Ans: c
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 : The bank of tubes at the back of domestic refrigerator are (a) condenser tubes (b) evaporator tubes (c) refrigerant cooling tubes (d) capillary tubes
Description : Domestic refrigerator working on vapour compression cycle uses the following type of expansion device (a) electrically operated throttling valve (b) manually operated valve (c) thermostatic valve (d) capillary tube
Last Answer : Ans: d
Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating
Description : Rating of a domestic refrigerator is of the order of (a) 0.1 ton (b) 5 tons (c) 10 tons (d) 40 tons
Description : Identify modes of heat transfer involved applications with brief explanation. (1) Radiator of automobile (2) Condenser of domestic refrigerator.
Last Answer : Modes of heat transfer Automobile radiator-A radiator is a type of heat exchanger. It is designed to transfer heat from the hot coolant that flows through it to the air blown through ... of heat transfer plays very important deciding factor transferring heat from condenser tube to atmosphere.
Description : The COP of a vapour compression plant in comparison to vapour absorption plant is (a) more (b) less (c) same (d) more/less depending on size of plant
Description : The size of inlet valve of an engine in comparison to exhaust valve is A. more B. less C. same D. varies from design to design
Last Answer : ANSWER : B
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 : 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 : In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is (a) less than 2 kg (b) more than or equal to 3.65 kg (c) more than 10 kg (d) there is no such consideration
Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency
Last Answer : Ans :c
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 : Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers
Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction
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 : Pick up the incorrect statement (a) lithium bromide used in vapour absorption cycle is nonvolatile (b) lithium bromide plant can't operate below 0°C (c) a separator is used in lithium ... of solution coming out of lithium bromide generator is more in comparison to that entering the generator
Description : If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressorrequired will be (a) same (b) more (c) less (d) more/less depending on rating
Description : The specific fuel consumption of a petrol engine compared to diesel engine of same H.P is A. same B.more C. less D. unpredictable
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
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 : 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 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 : 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 : Formation of frost on evaporator in refrigerator (a) results in loss of heat due to poor heat transfer (b) increases heat transfer rate (c) decreases compressor power. (d) can be avoided by proper design
Description : Condensing temperature in a refrigerator is the temperature (a) of cooling medium (b) of freezing zone (c) of evaporator (d) at which refrigerant gas becomes liquid
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 : The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat
Description : The vapour compression refrigerator employs the following cycle (a) Rankine (b) Carnot (c) Reversed Carnot. (d) Brayton
Description : The air requirement of a petrol engine during starting compared to the theoretical air requirement for complete combustion is A. more B.unpredictable C. same D. less
Last Answer : ANSWER : D
Description : The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is A. Less B. More C. Same D. Unpredictable
Description : The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is a. more b. less c. same d. may be more or less depending on engine capacity
Last Answer : ANSWER b. less
Description : Volumetric efficiency of a compressor without clearance volume A. Increases with increase in compression ratio B. Decreases wit increase in compression ratio C. Not dependent upon compression ratio D. Unpredictable
Last Answer : ANSWER : C
Description : Standard air is the: a. Mass of 1 cubic meter of dry air at 20°C and atmospheric pressure b. Mass of a cubic meter of air at atmospheric conditions c. Volume of air at ambient temperature and atmospheric pressure ... pressure at sea level or 101.325 kPa e. Volume of 1 kg of air at 15°C and 100 kPa
Last Answer : Answer: D
Description : Wet-bulb temperature is: a. The temperature indicated by a thermometer whose bulb covered by a water-wetted wick and exposed to a rapidly moving stream of air b. The same as the dry-bulb ... point temperature d. Always less than the dry-bulb temperature e. Not required to find the relative humidity
Last Answer : Answer: A
Description : Dry-bulb temperature is: a. The absolute temperature corresponding to the atmospheric pressure b. The same as the wet-bulb temperature if the relative humidity is less than 100% c. Not required ... d. The temperature of the air measured with an ordinary thermometer e. The dew point temperature
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 : Small amount of gasoline is added to alcohol to a) reduce the emission b) to increase the power output c) to increase the efficiency d) to improve cold weather starting
Last Answer : Answer: d Explanation: None.
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 dew point temperature is less than the wet bulb temperature for A. saturated air B. unsaturated air C. both saturated and unsaturated air D. none of the above
Description : Air fuel ratio at which a petrol engine cannot work is A. 8:1 B. 12:1 C. 15:1 D. 20:1 and less
Description : The heating value per unit volume of hydrogen gas is less than ______________ that of air. a) 1/12th b) 1/10th c) 2/3rd d) 1/3rd
Last Answer : Answer: d Explanation: None
Description : Hydrogen gas has less than _______________ the density of air. a) 1/12th b) 1/10th c) 2/3rd d) 1/3rd
Last Answer : Answer: b Explanation: None.
Description : Air fuel ratio at which a petrol engine cannot work is a. 8:1 b. 10:1 c. 20:1 and less d. 15:1
Last Answer : ANSWER c. 20:1 and less
Description : Compressor at high altitude will draw A. More power B. Less power C. Same power D. Unpredictable
Description : Diesel as compared to petrol is a. more difficult to ignite b. less difficult to ignite c. highly ignitable d. just about the same difficult to ignite
Last Answer : ANSWER a. more difficult to ignite
Description : In diesel engine, the compression ratio as compared with the expansion ratio is a. same b. less c. more d. variable
Last Answer : ANSWER c. more