Air standard cycle uses ____ as a working medium. a. Perfect gas b. Real gas c. Ideal gas d. Natural gas  

1 Answer

Answer :

ANSWER  a. Perfect gas  

Related questions

Description : An ideal air standard Otto cycle has a compression ratio of 8.5. If the ratio of the specific heats is 1.4, then what is thermal efficiency (in percentage) of the Otto cycle? a. 57.5% b. 45.7% c. 52.5% d. 95%

Last Answer : ANSWER a. 57.5%

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 : 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 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 : A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel ... an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.

Last Answer : ANSWER c. The compression ratio of a diesel engine is higher than that of an S.I engine

Description : For an engine operating on air standard Otto cycle, the clearance volume is 10% of the swept volume. The specific heat ratio of air is 1.4. The air standard cycle efficiency is a. 38.3 % b. 39.8 % c. 60.2 % d. 61.7 %

Last Answer : ANSWER d. 61.7%

Description : The air standard Otto cycle comprises a two constant pressure processes and two constant volume processes b two constant pressure and two constant entropy processes c. two constant volume processes and two constant entropy processes d. none of the above.

Last Answer : ANSWER (c) two constant volume processes and two constant entropy processes

Description : The characteristic equation of gases pv = mRT holds good for (a) mono atomic gases (b) diatomic gases (c)real gases (d) ideal gases

Last Answer : Ans: c

Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) gas liquefaction (c)commercial refrigerators (d) Chillers

Last Answer : Ans: b

Description : Air refrigeration cycle is used in (a) domestic refrigerators (b) commercial refrigerators (c) air conditioning (d) gas liquefaction

Last Answer : Ans: d

Description : What is the perfect condition for dehumidification of air? A. air is heated above its dew point temperature B. air is cooled up to its dew point temperature C. air is heated below its dew point temperature D. air is cooled below its dew point temperature

Last Answer : ANSWER : D

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 : 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

Last Answer : ANSWER : B

Description : In a two stage reciprocating air compressor with a suction pressure of 2 bar and delivery pressure of 8 bar the ideal intercooler pressure will be A. 10 bar B. 6 bar C. 4 bar D. 3 bar

Last Answer : ANSWER : C

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 : If the compression ratio of an engine working on Otto cycle is increased from 5 to 7 the percentage increase in efficiency will be a. 2% b. 4% c. 8% d. 14%

Last Answer : ANSWER d. 14%

Description : When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned

Last Answer : ANSWER : B

Description : Which of the following medium is compressed in a diesel engine cylinder? a. air b. air and fuel c. air and lubricating oil d. fuel

Last Answer : ANSWER a. air

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

Last Answer : Ans: d

Description : Describe with neat sketch working of natural draft cooling towers.

Last Answer : Natural draft cooling tower: -In natural draught cooling tower, the circulation of air is produced by the pressure difference of air inside the tower and outside atmospheric air Hot cooling water falls down ... the pressure difference of air inside and outside of cooling tower (natural flow).

Description : The volume of standard air is _____ m3/kg of dry air. a. 0.533 b. 0.633 c. 0.733 d. 0.833 e. 0.933

Last Answer : Answer: D

Description : The specific volume of air is expressed as the volume of: a. 1 kg of air at 101.325 kPa in cm3 b. 0.833 kg of air at standard pressure and temperature in m3 c. 1 kg of air at 101.325 ... d. 1 g of air occupied at any temperature and pressure e. 1 kg of air, regardless of temperature and pressure

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 : Which of the following cycles uses air as the refrigerant? (a) Ericsson (b) Stirling (c) Carnot (d) Bell-coleman

Last Answer : Ans: d

Description : The cooling tower uses the phenomenon of evaporative cooling to cool warm water above the dbt of air. A. true B. false

Last Answer : ANSWER : B

Description : Air refrigeration operates on (a) Carnot cycle (b) Reversed Carnot cycle (c) Rankine cycle (d) Brayton cycle.

Last Answer : Ans: d

Description : Whencrudeoilisheated, which of thefollowinghydrocarbonisgiven off first A. kerosene C. gasolene C. natural gas D. paraffin

Last Answer : ANSWER : C

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 : In adiabatic evaporative cooling, heat transfer between chamber and surroundings is ____ A. zero B. high C. low D. none of the mentioned

Last Answer : ANSWER : A

Description : Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer

Last Answer : Ans: a

Description : Pick up the correct statement about giving up of heat from one medium to other in ammonia absorption system (a) strong solution to weak solution (b) weak solution to strong solution (c) strong solution to ammonia vapour (d) ammonia vapour to strong solution.

Last Answer : Ans: b

Description : In refrigerators, the temperature difference between the evaporating refrigerant and the medium being cooled should be (a) high, of the order of 25° (b) as low as possible (3 to 11°C) (c) zero (d) any value

Last Answer : Ans: b

Description : In a typical medium speed 4- stroke Diesel engine, the inlet valve A. opens 20°before top dead centre and closes at 35°afterthebottomdead centre. B. opens up at top dead centre and closes at bottomdead centre C. may open orcloseanywhere D. remains open for 200°

Last Answer : ANSWER : A

Description : An ideal gas whose specific heats are constant is called _____.  A. Perfect gas  B. Natural gas  C. Artificial gas  D. Refined gas

Last Answer : Perfect gas

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 : 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 : 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 : 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 : Absorption system normally uses the following refrigerant (a) Freon-11 (b) Freon-22 (c) C02 (d) ammonia.

Last Answer : Ans: e

Description : The domestic refrigerator uses following type of compressor (a) centrifugal (b) axial (c) miniature sealed unit (d) piston type reciprocating

Last Answer : Ans: d

Description : Heat engine uses ______ energy to produce mechanical work. a. Thermal b. Fluid c. Kinetic d. Electric (Ans:a)

Last Answer : Which of the following is not an internal Combustion (IC) engine? a. Gas engine b. Wankel engine c. Jet engine d. Stirling engine (Ans:d)

Description : Common rail injection system uses injection pressures of the order a) 100-200 bar b) 200-400 bar c) 400-600 bar d) 1500 bar

Last Answer : Answer: d Explanation: Generally, common rail injection system uses injection pressures of the order 1500 bar.

Description : D-MPFI system uses a) port injection b) direct injection c) manifold injection d) throttle body injection

Last Answer : Answer: b Explanation: D-MPFI system uses direct injection and L-MPFI system uses port injection while multipoint fuel injection system uses port injection and throttle body injection.

Description : L-MPFI system uses a) port injection b) direct injection c) manifold injection d) throttle body injection

Last Answer : Answer: a Explanation: L-MPFI system uses port injection while multi-point fuel injection system uses port injection and throttle body injection while D-MPFI system uses direct injection.