Interview Questions with answers _ Basic _ IC Engine _ Part 1

 Q: What is IC Engine?

Ans.: The internal combustion engine converts chemical energy into useful mechanical energy by burning fuel.

Chemical energy is released when the fuel-air mixture is ignited by the spark in the combustion chamber. The gas produced in this reaction rapidly expands forcing the piston down the cylinder on the power stroke.

Q: What is 2-Stroke Engine?

Ans.: A Two-stroke engine is an internal combustion engine in which the piston's two strokes are required to complete single thermodynamic cycle.

2-STROKE engine is designed by DUGLAD CLERK in 1880, the suction, compression, expansion and exhaust takes place during 2-stroke of piston.

Interview Questions with answers

Q: What is 4-Stroke Engine?

Ans.: A four-stroke engine is an internal combustion engine in which the piston's four separate strokes are required to complete single thermodynamic cycle.

A 4-stroke engine is an internal combustion engine in which  the piston completes four separate strokes— intake, compression, power, and exhaust— during two separate revolutions of the engine’s crankshaft, and one single thermodynamic cycle.

Q: Definition of Octane Number and Cetane Number?

Ans.: Octane No. - Octane number is defined as the percentage, by volume, of iso-octane in the mixture of iso-octane and h-heptane. It is the measure of rating of SI engine.

Cetane No. - Cetane number is defined as the percentage, by volume, of n-cetane in the mixture of n-cetane and alpha methyl naphthalene. It is the measure of rating of CI engine.

Q: Name the main steps involve in 4-stroke IC engine?

Ans.:  The steps involved here are:

Intake stroke: The mixture of Air and Fuel are drawn in.

Compression stroke: Fuel vapor and air are compressed and ignition takes place.

Combustion stroke: Fuel combustion takes place and piston is pushed downwards.

Exhaust stroke: Exhaust is driven out.

Q: Among two-stroke engine and four-stroke engine which is generally preferred and why??

Ans.: Two stroke engine is generally preferred. Because it has smaller size for the same output.

Q: During idling process, a petrol engine requires lean or rich mixture??

Ans.: Lean mixture.

Q. What are the applications of IC engine?

Ans.: Automobiles, Aircraft vehicles, helicopters, Motorbikes, Boats and other locomotives.

Major power plants and similar naval applications.

Q: What are the advantages of lubrication in iC Engine?

Ans.:

It reduces the wear and tear of the moving parts.

It damps down the vibration of the engine.

It cleans the moving parts.

It makes the piston gas tight.

Q: Name the fuel used by IC Engines?

Ans.:

Petroleum:  Petroleum spirit, Petroleum diesel, liquefied petroleum gas(LPG), Compressed natural gas, Jet fuel ,Residual fuel.

Coal: Methanol, Gasoline, Diesel fuel.

Biofuels and Veg Oils:  Peanut oil and other veg oils, Biobutano, biodiesel, Dimethyl Ether, biogas, hydrogen.