Practice Test: Question Set - 01
1. In a typical medium speed 4-stroke cycle diesel engine the inlet valve
- (A) Opens at 20° before
top dead center and closes at 35° after the bottom dead center
- (B) Opens at top dead
center and closes at bottom dead center
- (C) Opens at 10° after
top dead center and closes 20° before the bottom dead center
- (D) May open or close
anywhere
2. The operation of forcing additional air under pressure into the engine cylinder is known as
- (A) Supercharging
- (B) Carburetion
- (C) Turbulence
- (D) Delay
period
3. Compression ratio of I.C. Engines is
- (A) The ratio of volumes
of air in cylinder before compression stroke and after compression stroke
- (B) Volume displaced by
piston per stroke and clearance volume in cylinder
- (C) Ratio of pressure
after compression and before compression
- (D) Swept volume/cylinder
volume
4. The air standard efficiency of an I.C. engine is given by (where r = Compression ratio, and γ = Ratio of specific heats)
- (A) 1 - rγ - 1
- (B) 1 +
rγ - 1
- (C) 1 -
(1/rγ - 1)
- (D) None
of these
5. Pick up the wrong statement about supercharging
- (A) Supercharging reduces
knocking in diesel engines
- (B) There can be limited
supercharging in petrol engines because of detonation
- (C) Supercharging at high
altitudes is essential
- (D) Supercharging results
in fuel economy
6. Number of working strokes per min. for a four stroke cycle engine are _________ the speed of the engine in r.p.m.
- (A) Equal to
- (B) One-half
- (C) Twice
- (D) Four-times
7. The theoretically correct air fuel ratio for petrol engine is of the order of
- (A) 6: 1
- (B) 9: 1
- (C) 12: 1
- (D) 15: 1
8. In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as
- (A) Scavenging
- (B) Detonation
- (C) Supercharging
- (D) Polymerisation
9. In the opposed piston diesel engine, the combustion chamber is located
- (A) Above the piston
- (B) Below the piston
- (C) Between the pistons
- (D) There is no such
criterion
10. The ignition of the charge by some hot surface within the engine before the passage of spark is called
- (A) Pre-ignition
- (B) Detonation
- (C) Ignition
delay
- (D) Auto-ignition
11. In a typical medium speed, 4-stroke cycle diesel engine
- (A) Fuel injection starts
at 10° before top dead center and ends at 20° after top dead center
- (B) Fuel injection starts
at top dead center and ends at 20° after top dead center
- (C) Fuel injection starts
at just before top dead center and ends just after top dead center
- (D) May start and end
anywhere
12. Which one of the following engines will have heavier flywheel than the remaining ones?
- (A) 30
kW four-stroke petrol engine running at 1500 r.p.m.
- (B) 30 kW
two-stroke petrol engine running at 1500 r.p.m.
- (C) 30 kW
two-stroke diesel engine running at 750 r.p.m.
- (D) 30 kW
four-stroke diesel engine running at 750 r.p.m.
13. Which of the following is the lightest and most volatile liquid fuel?
- (A) Diesel
- (B) Kerosene
- (C) Fuel oil
- (D) Gasoline
14. The working pressure and temperature inside the cylinder of an internal combustion engine is _________ as compared to a steam engine.
- (A) Low
- (B) Very low
- (C) High
- (D) Very high
15. The rating of a diesel engine, with increase in air inlet temperature, will
- (A) Increase linearly
- (B) Decrease linearly
- (C) Increase parabolically
- (D) Decrease
parabolically
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