Top 350+ Solved Heat Engines MCQ Questions Answer
Q. In a Carnot cycle the algebraic sum of the entropy changes for the cycle is
a. Zero
b. Either positive or negative
c. Negative
d. Depends on the properties of working substance
e. Positive
Q. Blue smoke from a diesel engine indicates the presence of
a. Unburnt carbon
b. Unburnt oil
c. Carbon dioxide
d. Carbon monoxide
e. Nitrous oxide
Q. A turbo-charger is used
a. In gas turbines for compression of air
b. For supercharging reciprocating engine
c. In jet propulsion units
d. In rockets for producing air fuel mixture
e. None of the above
Q. For same compression ratio and same heat input
a. Otto cycle is more efficient
b. Diesel cycle is more efficient
c. Both are equally efficient
d. None of the above
Q. Which is the external loss in a steam turbine?
a. Blade friction losses
b. Nozzle losses
c. Disc friction losses
d. Back pressure losses
e. Gland leakage losses
Q. 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
a. 0.007 kg/sq-cm
b. 0.14 kg/sq-cm
c. 1.04 kg/sq-cm
d. 1.14 kg/sq-cm
e. None of the above
Q. A cross-head has
a. Reciprocating motion
b. Rotory motion
c. Oscillating motion
d. (A) and (B) only
e. (A) and (C) only
Q. An average percentage of Carbon and Hydrogen in Petrol may be roughly given as
a. 70% C, 70% H2
b. 15% C, 85% H2
c. 50% C, 50% H2
d. 85% C, 150% H2
e. 60% C, 40% H2
Q. The overload capacity of diesel engine is usually around
a. 50%
b. Carbon dioxide
c. 1%
d. 25%
e. 10%
Q. 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
a. 5.5 ata
b. 3 ata
c. 4 ata
d. 7.5 ata
e. 5 ata
Q. In cse the exhaust silencer of a petrol engine is partly choked, it is likely to result in
a. Increased compression ratio
b. Increased fuel consumption
c. Reduced fuel consumption
d. Reduced compression ratio
e. None of the above
Q. Which of the following engine uses two fuel simultaneously?
a. Multi-fuel engine
b. Duel fuel engine
c. Wankle engine
d. Free piston gas generator
e. All of the above
Q. Which of the following constituent of air has the least proportion?
a. Carbon monoxide
b. Xenon
c. Argon
d. Helium
e. Neon
Q. Which of the following is a false statement. A multicylinder diesel engine is missing on one or more cylinders. The cause may be
a. Valve sticky
b. Insufficient fuel supply to cylinders
c. Compression poor
d. Air cleaner plugged
e. Valves leaky
Q. If a steam injector lifts the water but fails to force it into the boiler, the trouble may not be due to
a. Combining tube clogged
b. Insufficient steam pressure
c. Sry steam
d. Leake in water pipe
e. Any of the above