Internal Combustion Engines (I.C. Engines) MCQ Questions & Answers

Internal Combustion Engines (I.C. Engines) MCQ Questions & Answers | Mechanical Engineering

Learn Internal Combustion Engines (I.C. Engines) MCQ questions & answers are available for a Mechanical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. Internal Combustion Engines (I.C. Engines): MCQ question is the important chapter for a Mechanical Engineering and GATE students. Page-10 section-1

In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to

A) Prevent sparking across the gap between the points B) Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit C) Both (A) and (B) D) None of the above

Discuss

Answer & Solution

Answer: Option C

Solution:

In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to:
- Prevent sparking across the gap between the points
- Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit

The fuel in diesel engine is normally injected at pressure of

A) 5 - 10 kg/cm² B) 20 - 25 kg/cm² C) 60 - 80 kg/cm² D) 90 - 130 kg/cm²

Discuss

Answer & Solution

Answer: Option D

Solution:

The fuel in diesel engine is normally injected at pressure of 90 - 130 kg/cm².

The self ignition temperature of petrol is _________ as compared to diesel oil.

A) Same B) Lower C) Higher D) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

The self ignition temperature of petrol is higher as compared to diesel oil.

Which of the following statement is correct?

A) Compression ratio for petrol engines varies from 6 to 10 B) Higher compression ratio in diesel engines results in higher pressures C) Petrol engines work on Otto cycle D) All of the above

Discuss

Answer & Solution

Answer: Option D

Solution:

- Compression ratio for petrol engines varies from 6 to 10.
- Higher compression ratio in diesel engines results in higher pressures.
- Petrol engines work on Otto cycle.

The air standard efficiency of an I.C. engine depends on

A) Fuel used B) Speed of engine C) Compression ratio D) None of these

Discuss

Answer & Solution

Answer: Option C

Solution:

The air standard efficiency of an I.C. engine depends on Compression ratio. The compression ratio in I.C. engine is directly proportional to the thermal efficiency, so as it increases, then its thermal efficiency will increase. The thermal efficiency of petrol and gas engines is about 30% and the thermal efficiency of diesel engines is about 70%.

Scavenging air in diesel engine means

A) Air used for combustion sent under pressure B) Forced air for cooling cylinder C) Burnt air containing products of combustion D) Air used for forcing burnt gases out of engine's cylinder during the exhaust period

Discuss

Answer & Solution

Answer: Option D

Solution:

In automotive usage, scavenging is the process of pushing exhausted gas-charge out of the cylinder and drawing in a fresh draught of air or fuel/air mixture for the next cycle. This process is essential in having a smooth-running internal combustion engine.

If petrol is used in a diesel engine, then

A) Low power will be produced B) Efficiency will be low C) Higher knocking will occur D) Black smoke will be produced

Discuss

Answer & Solution

Answer: Option C

Solution:

If petrol is used in a diesel engine, then Higher knocking will occur

The calorific value of gaseous fuels is expressed in terms of

A) kcal B) kcal/kg C) kcal/m² D) kcal/m³

Discuss

Answer & Solution

Answer: Option D

Solution:

The calorific value of gaseous fuels is expressed in terms of kcal/m³.

A diesel engine has compression ratio from

A) 6 to 10 B) 10 to 15 C) 15 to 25 D) 25 to 40

Discuss

Answer & Solution

Answer: Option C

Solution:

A diesel engine has compression ratio from 15 to 25

100

A petrol engine has compression ratio from

A) 6 to 10 B) 10 to 15 C) 15 to 25 D) 25 to 40

Discuss

Answer & Solution

Answer: Option A

Solution:

A petrol engine has compression ratio from 6 to 10

Internal Combustion Engines (I.C. Engines) MCQ Questions &amp; Answers | Mechanical Engineering

Internal Combustion Engines (I.C. Engines) MCQ Questions & Answers | Mechanical Engineering