Practice Test: Question Set - 04
1. Flash point of fuel oil is
- (A) Minimum temperature
to which oil is heated in order to give off inflammable vapours in sufficient
quantity to ignite momentarily when brought in contact with a flame
- (B) Temperature at which
it solidifies or congeals
- (C) Temperature at which
it catches fire without external aid
- (D) Indicated by 90%
distillation temperature, i.e. when 90% of sample oil has distilled off
2. In petrol engines, advancing of the spark timing will _________ the knocking tendency.
- (A) Not
effect
- (B) Decrease
- (C) Increase
- (D) None
of these
3. In a naturally aspirated diesel engine, the air is supplied by
- (A) A supercharger
- (B) A centrifugal blower
- (C) A vacuum chamber
- (D) An injection tube
4. A supercharged engine as compared to an ordinary engine
- (A) Requires
smaller foundation
- (B) Is
lighter
- (C) Consumes
less lubricating oil
- (D) All
of these
5. Which of the following is not an intern’s combustion engine?
- (A) 2-stroke petrol engine
- (B) 4-stroke petrol
engine
- (C) Diesel engine
- (D) Steam turbine
6. The spark ignition engines are governed by
- (A) Hit
and miss governing
- (B) Qualitative
governing
- (C) Quantitative
governing
- (D) Combination
of (B) and (C)
7. Diesel engine can work on very lean air fuel ratio of the order of 30: 1. A petrol engine can also work on such a lean ratio provided
- (A) It is properly designed
- (B) Best quality fuel is
used
- (C) Cannot work as it is
impossible
- (D) Flywheel size is
proper
8. The object of providing masked inlet valve in the air passage of compression ignition engines is to
- (A) Enhance
flow rate
- (B) Control
air flow
- (C) Induce
primary swirl
- (D) Induce
secondary turbulence
9. In the crankcase method of scavenging, the air pressure is produced by
- (A) Supercharger
- (B) Centrifugal pump
- (C) Natural aspirator
- (D) Movement of engine
piston
10. The brake power (B.P.) of the engine is given by (where W = Brake load or dead load in newtons, l = Length of arm in meters, N = Speed of engine in r.p.m., S = Spring balance reading in newtons, D = Dia. of brake drum in meters, and d = Dia. of rope in meters)
- (A) B.P = (Wl × 2πN)/60 watts
- (B) B.P = [(W - S) πDN]/60 watts
- (C) B.P = [(W - S) π (D + d) N]/60 watts
- (D) All
of these
11. The temperature of interior surface of cylinder wall in normal operation is not allowed to exceed
- (A) 80°C
- (B) 120°C
- (C) 180°C
- (D) 240°C
12. Thermal efficiency of a two stroke cycle engine is _________ a four stroke cycle engine.
- (A) Equal to
- (B) Less
than
- (C) Greater
than
- (D) None
of these
13. Scavenging is usually done to increase
- (A) Thermal efficiency
- (B) Speed
- (C) Power output
- (D) Fuel consumption
14. If V₁ is the jet velocity and V₀ is the vehicle velocity, then the propulsive efficiency of a rocket is given by
- (A) [2(V₀/V₁)]/
[1 + (V₀/V₁)²]
- (B) (V₀/V₁)/ [1 + (V₀/V₁)²]
- (C) V₀/(V₀
+ V₁)
- (D) V₁/(V₀
+ V₁)
15. The pressure and temperature at the end of compression stroke in a petrol engine are of the order of
- (A) 4-6 kg/cm² and 200-250°C
- (B) 6-12 kg/cm² and 250-350°C
- (C) 12-20 kg/cm² and 350-450°C
- (D) 20-30 kg/cm² and 450-500°C
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