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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