Cooling And Lubrication In Automobile — Part 1 MCQs with Explanations

The correct answer is D: All are correct Here's why: When an engine runs too hot, several problems can occur: * Pre-ignition: This happens when the air-fuel mixture ignites before the spark plug fires. High engine temperatures can cause hot spots in the combustion chamber (like carbon deposits or glowing valves) to ignite the mixture prematurely. * Detonation (also known as 'Knocking' or 'Pinging'): This is an uncontrolled explosion of the air-fuel mixture in the cylinder. Instead of burning smoothly, the mixture detonates, creating shockwaves. Excessive heat significantly increases the risk of detonation. * Knocking: As mentioned above, Knocking is the same as detonation. So, since pre-ignition and detonation are caused by an engine running too hot, all options are correct.

Here’s why in simple terms: 1. It's not an "Open System": Automobile cooling systems are closed systems—they're sealed to prevent coolant loss and contamination. In an open system, the coolant would be exposed to the air, which isn’t the case here. 2. It's not technically a "High Pressure System": While the system is pressurized, it doesn’t qualify as a “high pressure system” in the typical engineering sense. The pressure is only slightly elevated to raise the boiling point of the coolant and improve heat transfer—not enough to be classified as "high pressure" like in hydraulics or steam systems. 3. So, “None of these” is the most accurate label: The cooling system is best described as a closed, pump-driven circulation system, which isn’t covered by the options A or B. Final Answer: Option D: None of these

Oil Strainer: This is the first step. It's like a big sieve that catches large pieces of dirt and debris in the oil pan. Oil Pump: This is the heart of the lubrication system. It sucks the oil from the strainer and pushes it through the system. Think of it as the engine that drives the oil flow. Relief Valve: This valve is a safety measure. If the oil pressure gets too high (e.g., when the engine is cold or the oil filter is blocked), the relief valve opens to release some of the oil back into the oil pan. This prevents damage to the engine. It protects from overpressure. Oil Filter: This is where the oil gets cleaned. The filter removes smaller particles of dirt and debris that the strainer missed. Clean oil is crucial for engine health. Cylinder Block & Cylinder Head: The clean oil then flows to the engine's critical parts: the cylinder block (where the pistons move) and the cylinder head (where the valves are). It lubricates these moving parts to reduce friction and wear. Oil Pan: Finally, after lubricating the engine, the oil flows back down to the oil pan, where it's ready to be pumped through the system again. This is where the oil collects .

Pressure and vacuum valve is the correct answer to “The radiator cap contains a”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Both is the correct answer to “What is the possible cause of poor circulation”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Any of them is the correct answer to “Fan is filled behind radiator which can have . . . . . . . . blades.”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All of these is the correct answer to “How the lubricant classified”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Temperature is the correct answer to “The main cause for changes in oil viscosity is”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Liquid lubricant is the correct answer to “Lard oil is a”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All of the above is the correct answer to “What is the advantages of a water cooled system”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Aluminium is the correct answer to “Which of the following is much better heat conductor”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

High is the correct answer to “Friction is . . . . . . . . when the material is shoft.”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All of these is the correct answer to “Grease is prepared by saponification of”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Calcium based greases is the correct answer to “. . . . . . . . are fairly water proof and are useful for water pumps, chassis and wheels bearings.”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Pressure valve is the correct answer to “If the coolant temperature rises and the pressure inside the radiator exceeds a predetermined level, which valve in the radiator cap will open”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All of the above is the correct answer to “The function of piston ring in an internal combustion engine is”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Option "Society of Automobile Engineers" is the correct answer for this question under Cooling And Lubrication In Automobile.

All are correct is the correct answer to “Essential requirements of good lubricating oil is/are-”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Crankcase ventilation is the correct answer to “A measure used to remove the combustion gases from the crankcase is called”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Decreased is the correct answer to “Thermal efficiency is . . . . . . . . due to more loss of heat to the cylinder walls.”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Both are correct is the correct answer to “Running the engine too cold will result in-”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Wearing out of rubbing metallic surface is the correct answer to “A lubricant is used primarily to prevent”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All are correct is the correct answer to “Which of the following method is used for engine cooling”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Thermo system is the correct answer to “Which is not the category of Pump Circulation”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Higher is the correct answer to “In liquid cooling method, instead of water, other liquids having . . . . . . . . boiling points are used for cooling.”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Rotor type pump is the correct answer to “The type of oil pump which has a gear pump that incorporates an inner rotor and outer rotor is”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Presence of moisture and oxygen is essential is the correct answer to “For corrosion of iron to takes place,”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Run the vehicle smoothly taking least load is the correct answer to “Lubricant is necessary to”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All are correct is the correct answer to “What is the possible cause of external leakage”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Both is the correct answer to “The lubricating system is-”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Brass is the correct answer to “The radiator core is made of”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Water with anti-freeze and anti-rust additives is the correct answer to “The fluid used as the heat carrying medium in the cooling systems of vehicles is”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Jackets is the correct answer to “To ensure effective cooling, each cylinder is surrounded by water”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Upper tank - Radiator core - Lower tank is the correct answer to “The correct flow sequence of coolant is”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

The engine should be stopped immediately is the correct answer to “When the pressure gauge registers no pressure at all then”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Filtered air from the engine air intake is circulated in the crankcase is the correct answer to “In case of the positive crankcase ventilation system”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

Impeller is the correct answer to “The pump part that rotates and causes water circulation between the radiator and engine is called”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All are correct is the correct answer to “The thickness of the film between the bearing and journal depends upon-”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

From top to bottom is the correct answer to “Under normal conditions, the water in the radiator circulates”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.

All are correct is the correct answer to “The lubricant used for clock and watches is-”. This question is standard in competitive examination syllabi for Cooling And Lubrication In Automobile.