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This set of Heat Engines Multiple Choice Questions & Answers (MCQs) focuses on Heat Engines Set 20

Q1 | If engines of different horse power, rpm, cylinder dimensions are to be compared for their performance, the parameter of comparison could be
  • Mean effective pressure
  • Specific speed
  • Exhaust temperature
  • Fuel consumption
  • Unit speed
Q2 | Ambassador car engine is
  • F-type
  • Overhead valve type
  • Side valve type
  • L-type
  • Overhead inlet and side exhaust type
Q3 | Which of the following chemical acts as anti-freeze?
  • Naphtha
  • Glycol
  • Ethyl alcohol
  • Lead acetate
  • n-heptane
Q4 | A low pressure accumulator is generally used with which of the following turbine
  • Mixed pressure turbine
  • Back pressure turbine
  • Impulse turbine
  • Condensing turbine
  • Reaction turbine
Q5 | Which is not the cause for loss of heat in boiler due to incomplete combustion?
  • Under cooling of furnace at low ratings
  • Improper secting of boiler
  • Insufficient air supply
  • Boiler drum uninsulated
  • Fuel bend in proof condition
Q6 | Temporary hardness of water is caused by
  • Bicarbonates of calcium and magnesium
  • Sulphates of calcium and magnesium
  • Chlorides of calcium and magnesium
  • Nitrates of calcium and magnesium
  • None of the above
Q7 | Crankcase explosion occurs in
  • Four stroke SI engines
  • Four stroke Cl engines
  • Two stroke Cl engines
  • Gas engines
  • Two stroke SI engines
Q8 | Which of the following offers best resistance to knocking in S.I. engines?
  • Aromatics
  • Paraffins
  • Carbon dioxide
  • Naphthenes
  • Olefins
Q9 | Which of the following engine can work on very lean mixture?
  • Petrol engine
  • Diesel engine
  • Two stroke engine
  • Wankel engine
  • Four stroke engine
Q10 | Overall thermal efficiency of a thermal power plant is
  • Carnot cycle efficiency
  • 50 to 70% of theoretical efficiency
  • Product of boiler efficiency, turbine efficiency and generator efficiency
  • Rankine cycle efficiency
  • None of the above
Q11 | In gas and petrol engines thermal efficiency may be expected in the range
  • 50 percent
  • 30 to 35 percent
  • 10 - 15 percent
  • 15 to 25 percent
  • 60 percent
Q12 | A 200 MW generator should be cooled by
  • Nitrogen
  • Hydrogen peroxide
  • Hydrogen
  • Water
  • Air
Q13 | Which of the following exists as highest pressure in a diesel engine
  • Exhaust gases in silencer
  • Lubricating oil
  • Fuel at the time of injection
  • Air at the end of compression stroke
  • Air during suction
Q14 | A camshaft is not provided in case of
  • Two stroke engines
  • High speed engines
  • Multicylinder engines
  • ir cooled engines
  • Vertical engines
Q15 | The compression ratio in case of a gas turbine is of the order of
  • 7
  • 12
  • 20
  • 5
  • 24
Q16 | Corona is generally accompanied by a faint glow and
  • Spark
  • Sparking
  • Heating of conductors
  • Explosion
  • Hissing noise
Q17 | If after some use the lower part, electrodes and beathing space of a spark plug are found coated by deposits of soot and carbon, the conclusion will be
  • Spark plug is of proper heat rating
  • Spark advance is incorrect
  • Spark plug is short circuited
  • Composition of mixture in the engine is correct
  • Spark plug is of too high heat rating
Q18 | As the compression ratio increases the volumetric efficiency of air compressor
  • Increases
  • Decreases
  • Does not change
  • Unpredictable
  • None of the above
Q19 | A fan is being used under certain conditions. If the fan speed is doubled the power requirement will be
  • 8 times
  • 16 times
  • Unchanged
  • Double of the original
  • Four times
Q20 | A jet engine has
  • Propeller on top
  • No propeller
  • Propeller in back
  • Two propellers
  • Propeller in front
Q21 | In jet engines the compression ratio
  • Varies with altitude
  • Varies with square of speed
  • Varies as cube of speed
  • Remains constant
  • None of the above
Q22 | Steam trap is a device that
  • Allows passage of water but prevents the passage of steam
  • Allows passage of air but prevents passage of steam
  • Allows passage of the flue gases but prevents flow of steam
  • None of the above
  • Chain grate stokers