Description : The dew point is the: a. Dry bulb temperature on a psychrometer b. Temperature at which water vapour will start to be absorbed into the air c. Temperature below which water vapour will start to ... vapour will start to condense out of the air e. Temperature at which water will start to evaporate
Last Answer : Answer: C
Description : Dew point can be best defined as the: a. Absolute temperature at which air, upon heating, will evaporate moisture b. . Percentage of moisture that air can hold at a given temperature ... to condense should the temperature drop further e. . Atmospheric pressure at which air will condense moisture
Last Answer : Answer: D
Description : Critical temperature is defined as the temperature above which a gas will (A) Not liquify (barring exceptions) (B) Immediately liquify (C) Never liquify however high the pressure may be (D) None of these
Last Answer : (C) Never liquify however high the pressure may be
Description : Critical pressure of a liquid is the pressure (a) above which liquid will remain liquid (b) above which liquid becomes gas (c) above which liquid becomes vapour (d) above which liquid becomes solid
Last Answer : Ans: a
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
Last Answer : Ans: d
Description : In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour
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
Last Answer : Ans: b
Description : The critical spark energy required to ignite a given mixture A. decreases with decreasing sparking voltage B. increases with decreasing sparking voltage C. increases with increasing sparking voltage D. decreases with increasing sparking voltage
Last Answer : ANSWER : D
Description : Are there any materials that liquefy when you heat them to a certain temperature, but turn solid again if you heat them any higher?
Last Answer : Needs to be fully reversible, of course.
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 : The _____________ sensor, checks the temperature of the ambient air entering the engine for fine tuning the mixture strength. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature
Last Answer : Answer: d Explanation: The air inlet temperature sensor, checks the temperature of the ambient air entering the engine for fine tuning the mixture strength whereas the engine temperature sensor senses the ... gas senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio.
Description : The _____________ sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature
Last Answer : Answer: c Explanation: The air flow sensor, monitors mass or volume of air flowing into the intake manifold for adjusting the quantity of fuel while exhaust gas senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio.
Description : The _____________ sensor senses the temperature of the engine coolant, and from this data the computer adjusts the mixture strength to rich side for cold starting. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature
Last Answer : Answer: a Explanation: The engine temperature sensor senses the temperature of the engine coolant, and from this data the computer adjusts the mixture strength to rich side for cold starting while the ... gas senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio.
Description : In _____________ sensor, output voltage changes in proportion to air-fuel ratio. a) engine temperature b) exhaust gas c) air flow d) air inlet temperature
Last Answer : Answer: b Explanation: Only in exhaust gas sensor, output voltage changes in proportion to air-fuel ratio.
Description : _____________ senor senses the amount of oxygen in the engine exhaust and calculates air-fuel ratio. a) Engine temperature b) Exhaust gas c) Air flow d) Air inlet temperature
Last Answer : Answer: b Explanation: Exhaust gas senor senses the amount of oxygen in the engine exhaust and calculates airfuel ratio while engine temperature sensor senses the temperature of the engine coolant, and from this data the computer adjusts the mixture strength to rich side for cold starting.
Description : Does the word liquefy have anything to do with the word liquid?
Last Answer : Yes. Liquefy means to turn something into a liquid.
Description : I have a sugar cube made of honey. How to get it back to liquid? thank you for answer
Last Answer : Put the glass in warm (not hot) water.
Description : How do we liquefy gases?
Last Answer : Maybe
Description : A standard ice point temperature corresponds to the temperature of (a) water at 0°C (b) ice at - 4°C (c) mixture of ice, water and vapour under equilibrium conditions under NTP conditions (d) mixture of ice and water Under equilibrium conditions.
Last Answer : Ans: D
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 : 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 : 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
Last Answer : ANSWER : A
Description : A Mixture of dry air and water,the formation of fog starts when, A. air temperature is equal to the dew point temperature B. air temperature is greater than the dew point temperature C. both a. and b. D. none of the above
Description : The temperature at which the air cannot hold all the water vapour mixed in it and some vapour starts condensing is called as A. humidification temperature B. dehumidification temperature C. dew point temperature D. none of the above
Last Answer : ANSWER : C
Description : When dry bulb temperature (DBT) and wet bulb temperature (WBT) are measured, greater the difference between DBT and WBT, A. greater the amount of water vapour held in the mixture B. smaller the amount of ... the mixture C. same the amount of water vapour held in the mixture D. none of the above
Last Answer : ANSWER : B
Description : The temperature of air recorded by thermometer when the bulb is covered by a cotton wick saturated by water is called as A. dry bulb temperature B. wet bulb temperature C. stream temperature D. psychrometric temperature
Description : What is the temperature at which the water vapour in the mixture of water vapour in air, starts condensing called? A. condensation temperature B. dew point temperature C. vaporization temperature D. all of the above
Description : The knocking tendency in CI engines increases with (a) Increase of coolant water temperature (b) Increase of temperature of inlet air (c) Decrease of compression ratio (d) Increase of compression ratio
Last Answer : Ans :c
Description : The tendency of knocking in CI engine reduces by (a) High self ignition temperature of fuel (b) Decrease in jacket water temperature (c) Injection of fuel just before TDC (d) Decrease in injection pressure
Description : In SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature
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 : Supercharging is essential in A. aircraft engines B. petrol engines C. gas turbines D. diesel engines
Description : Whencrudeoilisheated, which of thefollowinghydrocarbonisgiven off first A. kerosene C. gasolene C. natural gas D. paraffin
Description : The energy of expanding gas is transferred by piston to connecting rod through a. Crank pin b. Gudgeon pin c. Bearing d. Crankcase (Ans:b)
Last Answer : Which of the following is not used in four stroke compression-ignition (CI) engines? a. Fuel pump b. Spark plug c. Fuel injector d. Inlet and outlet Valves (Ans:b)
Description : Octane of natural gas is a) 60-80 b) 80-100 c) >100 d)
Last Answer : Answer: c Explanation: The octane number of natural gas is always >
Description : Major constituent of natural gas is a) ethane b) methane c) butane d) propane
Last Answer : Answer: b Explanation: Only methane is the major constituent of natural gas.
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 : A gas engine has a volume of 300 cc and clearance volume of 25 cc. Its volumetric efficiency is 0.8 and mech efficiency is 0.9. What is the volume of the mixture taken in per stroke? (a) 248 cc (b) 252 cc (c) 264 cc (d) 286 cc
Last Answer : Ans : c
Description : In a petrol engine, which of the following gas gets exhausted out without burning and without transformation? a. CO2 b. CO c. O2 d. N2
Last Answer : ANSWER d. N2
Description : Which of the following is not an internal combustion engine? a. petrol engine b. steam turbine c. diesel engine d. gas turbine
Last Answer : ANSWER b. steam turbine
Description : A spark plug is used in a. petrol engine b. diesel engine c. gas engine d. steam engine
Last Answer : ANSWER a. petrol engine
Description : For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.
Last Answer : ANSWER a. CP – CV = R
Description : Air standard cycle uses ____ as a working medium. a. Perfect gas b. Real gas c. Ideal gas d. Natural gas
Last Answer : ANSWER a. Perfect gas
Description : An ideal gas is heated at constant volume and then expanded isothermally. Show processes on P-V & T-S diagrams.
Last Answer : Process 1-2 : Constant volume process Process 2-3 : Constant temperature process (Isothermal process)
Description : A gas is compressed from 1 bar and 30°C to 5 bars and 30°C. Identify process and show on PV diagram.
Last Answer : Gas is compressed from (1) 1 bar 30 0C to (2) 5 bar 30 0C Temp is constant. Hence process is isothermal. P x V = Constant
Description : A psychrometer (pron: si-'kro-me-ter) is used to measure humidity. It consists of two thermometers, one of which is wetted. The water is allowed to evaporate. Which thermometer reads the higher temperature. w) the wet one x) the dry one
Last Answer : ANSWER: X -- THE DRY ONE
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