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This set of Heat Engines Multiple Choice Questions & Answers (MCQs) focuses on Heat Engines Set 7

Q1 | The air standard efficiency of a Diesel engine depends on
  • Speed
  • Torque
  • Thermodynamic properties of working fluid
  • Cetane value of fuel used
  • Compression ratio
Q2 | The size of a steam engine is 200 x 250 - 300 r.p.m. In this 200 indicates
  • Shaft diameter
  • Steam pressure in 1bs/sq. in.
  • Piston stroke
  • Horse power
  • Cylinder bore
Q3 | In multistages turbines by introducting reheating
  • Thermal efficiency improves
  • The output of turbine increases
  • Work done by compressor reduces
  • The ratio compressor compressor work/turbine output decreases
  • None of the above
Q4 | In order to reduce wear and eliminate scuffing, piston ring in internal combustion engines are
  • Made of soft material
  • Provided with grooves
  • Lubricated thoroughly
  • Made of square section
  • Plated with chromium, cadmium or phosphate
Q5 | The ends of piston rod in steam engines are connected to
  • Connecting rod and cross-head
  • Crankshaft and cross-head
  • Piston and crankshaft
  • Piston and cross-head
  • Connecting rod and crankshaft
Q6 | One horse power-hr is equal to
  • 1 kWh
  • 632 kcal
  • 100,000 kJ
  • 107 Joules
  • None of the above
Q7 | Which of the following boiler uses exhaust of the engine to produce draught?
  • Lamont boiler
  • Cornish boiler
  • Babcock and wilcox boiler
  • Lancashire boiler
  • Locomotive boiler
Q8 | In jet engine the compression ratio
  • Varies with altitude
  • Varies with speed
  • Varies as square of speed
  • Remains constant
  • None of the above
Q9 | Pour point is the temperature at which oil
  • Starts cracking
  • Will start flowing
  • Barely flows
  • Will ignite
  • Will give off vapours enough for ignition
Q10 | Which one of the following factors will not assist in smooth running of a compression ignition engine?
  • Moderate rate of pressure rise
  • Short delay period
  • Minimum of after burning
  • High ignition temperature of fuel
  • None of the above
Q11 | In case of an opposed piston engine the combustion chamber
  • Is not provided
  • Is formed between two piston tops
  • Is provided towards crank case side
  • Is fitted outside the cylinder
  • None of the above
Q12 | Specific heat is
  • The amount of heat required to raise the temperature of a unit quantity of substance through 1?C
  • The amount of heat requred to change the state or condition under which a substance exists without changing its temperature
  • The ratio of quantity of heat required to raise the temperature of a given weight of any substance through 1?C to the quantity of heat required to raise the temperature of same weight of water through 1?C
  • The heat sensed by a mercury thermometer
  • None of the above
Q13 | In a diesel engine the injection pressure is of the order of
  • 1500 kg/cm2
  • 100 kg/cm2
  • 1000 kg/cm2
  • 40 kg/cm2
  • 500 kg/cm2
Q14 | If a water cooled compressor knocks during operation, the probable cause cannot be
  • Loose valve
  • Air filter choked
  • Too much clearance in crank pin
  • Excess cooling in intercooler
  • Loose flywheel or pulley
Q15 | Thermal efficiency of a compression ignition engine may be of the order of
  • 35%
  • 50%
  • 20%
  • 75%
  • 70%
Q16 | In centrifugal pumps suction head is
  • Vertical distance from supply level to pump centre line pump being level
  • (A) Above less suction friction heat
  • (A) Above less velocity heat
  • Any of the above
  • None of the above
Q17 | Maintenance requirements are least in case of
  • Electric locomotives
  • Carbon dioxide
  • Diesel locomotives
  • Steam locomotives
Q18 | The higher the temperature required to ignite diesel fuel,
  • Lower the octane number
  • Carbon dioxide
  • Lower the cetane number
  • Higher the cetane number
  • the higher the octane number
Q19 | In pumped storage systems, water is pumped
  • Upstream during peak load periods
  • Upstream during off peak periods
  • Upstream during off season
  • None of the above
  • None of the above
Q20 | The supercharging of diesel engine is done mainly to
  • Cool the engine
  • Increase the life of the engine
  • Increase the power output
  • Increase the speed
  • Reduce the cnoise from the engine
Q21 | In Eicher tractor the engine is
  • Air cooled
  • Horizontal
  • Multi-cylinder type
  • Low compression ratio petrol engine
  • Constant speed engine
Q22 | Air fuel ratio in a petrol engine fitted with dirty air cleaner as compared to that with clean air clearance will be
  • Not affected
  • Higher
  • Lower
  • Fluctuating
  • Depends on load
Q23 | Crankshafts are generally
  • Turned from bar stock
  • Die cast
  • Sand cast
  • Forged
  • Cold headed
Q24 | In a condensing steam engine
  • Exhaust steam is condensed in condenser
  • Exhaust steam is not recirculated
  • Steam condenses as soon as it leaves the cylinder
  • Condensed steam is supplied
  • Steam condenses inside cylinder
Q25 | The Apparatus used for the determination of calorific value of solid fuel is
  • Bunsen's apparatus
  • Photo calorimeter
  • Bomb calorimeter
  • Releigh apparatus
  • Osrat's apparatus