I.C Engines Objective Questions with Answers – Set 04

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Q1. A supercharged engine as compared to an ordinary engine

(A) Is lighter
(B) Requires smaller foundations
(C) Consumes less lubricating oil
(D) All of these

Answer:(D) All of these


Q2. Pick up the wrong statement

(A) 2-stroke engine can run in any direction
(B) In 4-stroke engine, a power stroke is obtained in 4-strokes
(C) Thermal efficiency of 4-stroke engine is more due to positive scavenging
(D) Petrol engines occupy more space than diesel engines for same power output

Answer: (D) Petrol engines occupy more space than diesel engines for same power output


Q3. Which of the following fuel has little tendency towards detonation?

(A) Benzene
(B) Iso-octane
(C) Normal heptane
(D) Alcohol

Answer: (B) Iso-octane


Q4. Installation of supercharger on a four cycle diesel engine can result in the following percentage increase in power

(A) Up to 35%
(B) Up to 50%
(C) Up to 75%
(D) Up to 100%

Answer: (D) Up to 100%


Q5. The exhaust valve in a four stroke cycle petrol engine

(A) Opens at 50° before bottom dead center and closes at 15° after top dead center
(B) Opens at bottom dead center and closes at top dead center
(C) Opens at 50° after bottom dead center and closes at 15° before top dead center
(D) May open and close anywhere

Answer: (A) Opens at 50° before bottom dead center and closes at 15° after top dead center


Q6. The correct mixture strength (by weight) for petrol is about

(A) 14.6 : 1
(B) 18.5 : 1
(C) 20.4 : 1
(D) 22.6 : 1

Answer: (A) 14.6 : 1


Q7. The increase in intake temperature of internal combustion engines will _ efficiency.

(A) Have no effect on
(B) Increase
(C) Decrease
(D) None of these

Answer: (C) Decrease


Q8. The air-fuel ratio of the petrol engine is controlled by

(A) Carburettor
(B) Injector
(C) Governor
(D) None of these

Answer: (A) Carburettor


Q9. 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

Answer: (D) Supercharging results in fuel economy


Q10. The probability of knocking in diesel engines is increased by

(A) High self ignition temperature
(B) Low volatility
(C) Higher viscosity
(D) All of these

Answer: (D) All of these


Q11. The loud pulsating noise heard within the cylinder of an internal combustion engine is known as

(A) Detonation
(B) Turbulence
(C) Pre-ignition
(D) Supercharging

Answer: (A) Detonation


Q12. 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

Answer: (D) Steam turbine


Q13. The purpose of testing an internal combustion engine is

(A) To determine the information, which cannot be obtained by calculations
(B) To conform the data used in design, the validity of which may be doubtful
(C) To satisfy the customer regarding the performance of the engine
(D) All of the above

Answer: (D) All of the above


Q14. For maximum power generation, the air fuel ratio for a petrol engine for vehicles, is of the order of

(A) 9 : 1
(B) 12 : 1
(C) 15 : 1
(D) 18 : 1

Answer:(B) 12 : 1


Q15. The function of a distributor in a coil ignition system of I.C. engines is

(A) To distribute spark
(B) To distribute power
(C) To distribute current
(D) To time the spark

Answer: (D) To time the spark


Q16. Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged?

(A) Yes
(B) No
(C) To some extent
(D) Unpredictable

Answer:(B) No


Q17. A petrol engine, during suction stroke draws

(A) Air only
(B) Petrol only
(C) A mixture of petrol and air
(D) None of these

Answer: (C) A mixture of petrol and air


Q18. The inlet value of a four stroke cycle I.C engine remains open for nearly

(A) 180°
(B) 125°
(C) 235°
(D) 200°

Answer: (C) 235°


Q19. If V₁ is the jet velocity and V₀ is the vehicle velocity, then propulsive efficiency of a turbojet engine is

(A) V₁ / (V₀ + V₁)
(B) V₀ / (V₀ + V₁)
(C) 2V₀ / (V₀ + V₁)
(D) 2V₁ / (V₀ + V₁)

Answer:(C) 2V₀ / (V₀ + V₁)


Q20. Most high speed compression engines operate on

(A) Diesel cycle
(B) Otto cycle
(C) Dual combustion cycle
(D) Special type of air cycle

Answer: (C) Dual combustion cycle


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