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This set of Heat Engines Multiple Choice Questions & Answers (MCQs) focuses on Heat Engines Set 2
Q1 | A gas used in gas engine trial was tested in a Boys Calorimeter. The pressure of gas supply was 7 cm of water column. If the barometric pressure is 760 mm of mercury, the absolute pressure of the gas would be
- 0.007 kg/sq-cm
- 0.14 kg/sq-cm
- 1.04 kg/sq-cm
- 1.14 kg/sq-cm
- None of the above
Q2 | A cross-head has
- Reciprocating motion
- Rotory motion
- Oscillating motion
- (A) and (B) only
- (A) and (C) only
Q3 | An average percentage of Carbon and Hydrogen in Petrol may be roughly given as
- 70% C, 70% H2
- 15% C, 85% H2
- 50% C, 50% H2
- 85% C, 150% H2
- 60% C, 40% H2
Q4 | The overload capacity of diesel engine is usually around
- 50%
- Carbon dioxide
- 1%
- 25%
- 10%
Q5 | A gas turbine plant operates between 1 ata and 9 ata with minimum and maximum cycle temperature of 25?C and 1000?C. A two stage compressor is provided with perfect intercooling and work is equally divided between the two stages. The intermediate pressure will be
- 5.5 ata
- 3 ata
- 4 ata
- 7.5 ata
- 5 ata
Q6 | In cse the exhaust silencer of a petrol engine is partly choked, it is likely to result in
- Increased compression ratio
- Increased fuel consumption
- Reduced fuel consumption
- Reduced compression ratio
- None of the above
Q7 | Which of the following engine uses two fuel simultaneously?
- Multi-fuel engine
- Duel fuel engine
- Wankle engine
- Free piston gas generator
- All of the above
Q8 | Which of the following constituent of air has the least proportion?
- Carbon monoxide
- Xenon
- Argon
- Helium
- Neon
Q9 | Which of the following is a false statement. A multicylinder diesel engine is missing on one or more cylinders. The cause may be
- Valve sticky
- Insufficient fuel supply to cylinders
- Compression poor
- Air cleaner plugged
- Valves leaky
Q10 | If a steam injector lifts the water but fails to force it into the boiler, the trouble may not be due to
- Combining tube clogged
- Insufficient steam pressure
- Sry steam
- Leake in water pipe
- Any of the above
Q11 | Which one of the following symptoms will not show that combustion is becessary complete.
- Presence of free carbon in exhaust
- Presence of carbon monoxide in exhaust
- Presence of oxygen in exhaust
- Presence of nitrogen in exhaust
- All of the above
Q12 | Presence of impurities in ice
- Does not have any effect
- Lowers melting point
- Makes it heavier than water
- Raises melting point
- Depends on other factors
Q13 | Piston rod is provided in
- Slow speed steam engines
- Double acting steam engines
- High speed steam engines
- Non-condensing steam engines
- Condensing steam engines
Q14 | The pressure of steam generated in a boiler as recorded by the Bourdon pressure gauge was 2.2 kg/sq-cm. If the barometer reads 774 mm of mercury the absolute pressure of steam would be
- 0.2 kg/sq-cm
- 9.774 kg/sq-cm
- 1.025 kg/sq-cm
- 77.4 mm of Hg
- 3.2526 kg/sq-cm
Q15 | Which statement is false in case of SI engines
- Accetylene has least tendency to knocking
- Adding methyl groups to the side of the carbon chain increases the knocking tendency
- Unsaturated aliphatic hydrocarbons show less knocking tendency
- Increasing the length of the carbon chain increases the knocking tendency
- Centralising the carbon atoms decreases the knocking tendency
Q16 | In a petrol engine as the speed increases
- The spark intensity has to be increased
- The spark intensity has to be reduced
- The spark has to be advanced
- The spark has to be retarded
- None of the above
Q17 | In thermodynamics, forced processes are those
- Where a difference is observed in any microscopic property of the system between different times of states
- Where a difference is observed in any microscopic property of the system between different times or states
- Which occur in the direction of an intensive property or driving force contained within the system
- Which require an agency outside the system to force the process
- None of the above
Q18 | The steam in a boiler drum is always
- Dry and saturated
- Wet or dry and saturated
- Dry
- Wet
- Superheated
Q19 | Which of the following is false statement? The cause of slow cranking of a gas engine during starting may be
- Partially discharged battery
- Under capacity battery
- High air temperature
- Heavy engine oil
- Faulty starting motor
Q20 | The work done on a compressor will be least when air is taken from
- As and where available
- Source of low temperature air
- A source at 0?C
- Atmosphere
- Source of high temperature air
Q21 | A coal contains 3.5% sulphur by weight, as fired, and all the sulphur may be assumed to go to formation of sulphur dioxide. How many tonnes of SO2 are produced per day of the firing rate is 35 tonnes per hour
- 54.8
- 60.8
- 48.8
- 58.8
- 100
Q22 | The total length of 40 mid-ordinates on a simple steam engine indicator diagram is 17 cm. The pressure scale is 0.6 kg/sq-cm. The mean effective pressure would be
- 1.0 kg/sq-cm
- 1.7 kg/sq-cm
- 1.0 kg/sq-cm
- 10.2 kg/sq-cm
- None of the above
Q23 | Free air is air at
- 1 kg/cm2 and 20?C
- 1 kg/cm2 and atmospheric temperature
- 1 kg/cm2 and 27?C
- 1 kg/cm2 and 0?C
- Atmospheric conditions at any specific location
Q24 | De-Laval turbine is mostly used
- For small powers at high speeds
- For small powers at low speeds
- For high powers at low speeds
- For high powers at high speeds
- None of the above
Q25 | Air fuel ratio for a jet engine is of the order of
- 15 ; 1
- 20 ; 1
- 60 ; 1
- 400 ; 1
- 10 ; 1