Description : The coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above
Last Answer : Ans: d
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
Last Answer : Ans: c
Description : What is the degree of saturation? A. the ratio of the actual relative humidity to the saturated specific humidity at the same temperature B. the ratio of the actual specific humidity to the ... specific humidity to the actual specific humidity at the same temperature D. none of the above
Last Answer : ANSWER : B
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
Last Answer : Ans: a
Description : For obtaining high COP, the pressure range of compressor should be (a) high (b) low (c) optimum (d) any value
Last Answer : Ans: b
Description : Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP
Description : Superheating in a refrigeration cycle (a) increases COP (b) decreases COP (c) COP remains unaltered (d) other factors decide COP
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
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 : The value of COP in vapour compression cycle is usually (a) always less than unity (b) always more than unity (c) equal to unity (d) any one of the above
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 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.
Description : 20. The coefficient of discharge is the ratio of theoretical discharge to the actual discharge through an orifice. A) True B) False
Last Answer : B
Description : Coefficient of contraction is the ratio of (A) Actual velocity of jet at vena contracta to the theoretical velocity (B) Loss of head in the orifice to the head of water available at the exit of the ... available at the exit of the orifice (D) Area of jet at vena-contracta to the area of orifice
Last Answer : Answer: Option D
Description : Coefficient of resistance is the ratio of (A) Actual velocity of jet at vena-contracta to the theoretical velocity (B) Area of jet at vena-contracta to the area of orifice (C) Loss ... available at the exit of the orifice (D) Actual discharge through an orifice to the theoretical discharge
Last Answer : Answer: Option C
Description : Coefficient of velocity is defined as the ratio of (A) Actual velocity of jet at vena contracta to the theoretical velocity (B) Area of jet at vena contracta to the area of orifice (C) Actual discharge through an orifice to the theoretical discharge (D) None of the above
Last Answer : Answer: Option A
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 : 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 : 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 : A two stroke engine has a speed of 750 rpm. A four stroke engine having an identical cylinder size runs at 1500 rpm. The theoretical output of the two stroke engine will (a) Be twice that of the four stroke ... ) Be the same as that of the four stoke (d) Depend upon whether it is a CI or SI engine
Last Answer : Ans :c
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 : Absolute or specific humidity is a) the actual mass of moisture present in a specific amount of air b) the maximum mass of moisture that a specific amount of air can hold c) the ratio of ... a specific amount of air at that absolute temperature e) a specific amount of air saturated with moisture
Last Answer : ANSWER : A
Description : The actual volume of fresh charge admitted in 4-stroke petrol engine is A. equal to stroke volume B. equal stroke volume and clearance volume C. less than stroke volume D. more than stroke volume
Last Answer : ANSWER : C
Description : Ratio of actual indicated work to hypothetical indicated work in a steam engine is the (a) Indicated thermal efficiency (b) Friction factor (c) Mechanical efficiency (d) Diagram factor
Last Answer : Ans : 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 : Sling psychrometer is used to measure A. only dry bulb temperature B. only wet bulb temperature C. dry and wet bulb temperature D. relative humidity
Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above
Description : The ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at the same temperature of the mixture is called as A. humidity B. partial humidity C. specific humidity D. relative humidity
Description : What is the relative humidity for a saturated air? A. 0% B. 50% C. 100% D. cannot say
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 : A device for measuring relative humidity is called: a. A dew point analyzer b. An R. H. gauge c. An aspirating gauge d. A psychrometer e. A chronometer
Last Answer : Answer: D
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 : The term "relative humidity" applies to a) the percentage of moisture in the air as compared to the amount of moisture the air can hold at a specific temperature b) the weight of the moisture in the air c) ... of the air d) the amount of moisture in the air e) the amount of humidity in the air
Description : Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb ... of dry air e) the ratio of the mass of water vapour divided by the mass of wet air
Description : The moisture content lines in psychrometric chart are also called as A. relative humidity lines B. specific humidity lines C. both a. and b. D. none of the above
Description : At 100% relative humidity, the wet bulb temperature is A. lower than the dew point temperature B. higher than the dew point temperature C. equal to the dew point temperature D. none of the above
Description : When the rate of evaporation of water is zero, the relative humidity of the air is A. 0% B. 100% C. 50% D. unpredictable
Description : When the dew point temperature is equal to the air temperature then the relative humidity is A. 0% B. 50% C. 100% D. unpredictable
Description : The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called a. net efficiency b. efficiency ratio c. relative efficiency d. overall efficiency
Last Answer : ANSWER c. relative efficiency
Description : Octane number of gasoline is obtained by comparing the performance of the engine when running on a mixture of the following hydrocarbons A. ethane and methane B. normal heptane and iso-octane C. iso-heptane and octane D. iso-octane and TEL
Description : In four stroke engine which of the following is also known as power stroke a. Suction stroke b. Compression stroke c. Expansion stroke d. Exhaust stroke (Ans:c) Measurements of fuel and air ... into IC engine,___________its efficiency A. increase B. decrease C. does not alter D. unpredictable on
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
Description : The compressor performance at higher altitude compare to sea level will be A. Same B. Higher C. Lower D. Unpredictable
Description : Which one of the following is correct? A. In a multistage compressor adiabatic efficiency is less than stage efficiency B. In a multistage turbine adiabatic efficiency is less than the stage ... compressor is greater than one D. Preheat factor does not affect the multistage compressor performance
Description : Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) ... flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values
Last Answer : (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature
Description : Cd , Cc and Cv are related (for flow through an orifice) as (where, Cd = discharge co-efficient, Cc = co-efficient of contraction = (area of jet at venacontracta/area of opening), Cv = co-efficient of velocity = (actual velocity ... A) Cd = Cc /Cv (B) Cd = Cc .Cv (C) Cd = Cv / Cc (D) None of these
Last Answer : (B) Cd = Cc .Cv
Description : Co-efficient of discharge (Cd ) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv ; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about (A) 0.42 (B) 0.62 (C) 0.82 (D) 0.98
Last Answer : (B) 0.62