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Right ANSWER is (B) Clutch

The explanation: The KNOB can be MANUALLY operated as it is connected to the clutch system and operated periodically using clutch action. By this system, all the impurities are removed from an edge type of oil FILTER.

Right answer is (c) 2

For EXPLANATION I would SAY: The RESISTANCE increases due to clogging of the filter element .the maximum permissible resistance is about 2 bars. The CARTRIDGE type is the most used in automobile engines.

The correct answer is (b) Proportional

Easy explanation: In an unfiltered SYSTEM, the ACCUMULATED impurities increase in direct proportion to the OPERATING TIME. As time passes by the impurities get accumulated due to which a regular SERVICE of the filtering system is required.

The correct CHOICE is (a) WIRE GAUZE

Easy explanation: The commonly used material for filtering is wire gauze, cotton, paper, etc. The filtering element must let the oil pass through without much resistance, but should prevent the undesirable particles from entering the oil galleries.

Right OPTION is (a) Central knob

Explanation: The oil is made to FLOW through the space between these discs and because of the very small spaces involved the IMPURITIES are left on the disc peripheries from where these are periodically removed by the simply operating central knob.

The correct answer is (a) Stack

Explanation: EDGE type oil filter is also known as a stack type. In this type, the oil is made to PASS through several closely spaced discs. These alternate discs are mounted over a CENTRAL spindle, while the discs in between these are attached to a SEPARATE fixed spindle.

The CORRECT choice is (a) Inlet

The best I can explain: The surface filter is installed on the inlet SIDE of the OIL pump.Whereas the secondary filter is installed on the OUTLET side of the oil pump and since the impurities in this are retained progressively along with the DEPTH of the filter material, it is also called depth filter.

The correct answer is (d) DIRTY exhaust fumes

For EXPLANATION: A oil filter should have high filtration EFFICIENCY and less pressure loss.excessive pressure loss occurs DUE to high resistance in the filter element, preventing oil from reaching all the engine parts and it should have a long LIFE and it should not produce any dirty exhaust fumes.

Correct OPTION is (b) 40-100

Best EXPLANATION: The spring-loaded relief valve is incorporated in the FILTER, which bypasses an emergency SUPPLY of unfiltered oil to the bearing to avoid bearing starvation is DESIGNED to open at 40 to 100kPa.

Correct CHOICE is (B) Doesn’t pass the filter

To explain I would say: In the bypass system the whole oil doesn’t pass through the filter at the same TIME. Most of the oil without being filtered goes to the BEARINGS whereas the rest passing through the filter is cleaned out and returned to the SUMP.

The correct choice is (c) 40-60

For explanation: The STRAINER which is more commonly KNOWN as the PRIMARY FILTER is formed from wire gauze of 40-60 MICROMETERS. The primary filter is also known as a surface filter since the impurities are retained on the outer surface of the filter.

Correct answer is (a) Crescent

The explanation is: Due to ECCENTRICITY, there is a SPACE in between two gears where the crescent space is placed. The crescent shape both offsets the IDLER gear and provides a seal between the SUCTION and discharge ports.

Correct option is (d) 25%

Explanation: The Rotor type pump is about 25% more EFFICIENT and COMPACT than the gear type pump. So, they are USED very widely in automobiles.

Correct choice is (C) To know the PRESSURE level

The best EXPLANATION: When the pressure exceeds the prescribed value, the SPRING is compressed and the ball is lifted off its seat and the oil passes back to the inlet side through the bypass provided.

Correct answer is (b) Less

The best I can explain: The lesser CLEARANCE would mean higher oil pressure DELIVERED at the outlet.Any restriction in the lubrication PASSAGES would also increase the oil pressure.

Right option is (d) 300-400KPa

To explain I WOULD say: The gear pump is always submerged in oil and the pump DELIVERS oil at about 300-400KPa. HENCE 300-400KPa is the RANGE of oil pressure.

Correct option is (b) RECIPROCATING

The best I can explain: PLUNGER pump is a reciprocating TYPE of pump in which the oil gets communicated from the inlet to the OUTLET by alternate SUCTION and pressure created by a reciprocating plunger.

The correct answer is (a) Less

The explanation is: In the ROTOR pump the outer rotor always has 1 less lobe when compared to the INNER rotor WHEREIN the extra space the oil GETS compressed.

Right ANSWER is (a) CLOCKWISE

The EXPLANATION is: Both the gears are meshed due to which the driving gear rotates anticlockwise and the DRIVEN gear rotates in the clockwise DIRECTION in a gear-driven gear pump.

Right CHOICE is (b) Different

Easy EXPLANATION: The AXES of rotation of the two ROTORS are different which causes the size of the spaces between them to vary.One of the rotors GETS its drive from an engine which causes the other rotor to rotate along with it.

The CORRECT choice is (a) Engine speed

The BEST I can explain: The OIL Pressure in the engine increases with the increase in engine speed which would increase the WORKING speed of the oil pump.

Right CHOICE is (d) 50-100

The best EXPLANATION: The oil pressure is maintained at 400-500kpa for the main and big-end bearing while about 50-100kpa pressure is USED for TIMING gears and camshaft bearing.

The correct choice is (d) all of the above

The explanation: The dry-sump is more RELIABLE, but is more COMPLEX and COSTLIER due to additional pump and high-pressure oil lines due to which it is not USED for small VEHICLES.

The correct choice is (a) 0.3

The explanation: At the end of the main oil gallery, and oil-pressure switch is provided which operates the warning LIGHT on the dashboard. When the oil pressure becomes LOWER than the specified VALUE 0.3 bar, the warning lights come on, to attract the driver’s ATTENTION.

The CORRECT choice is (a) pressure lubricating system

To ELABORATE: In heavy-duty engines during the oil circulation, the oil gains heat from various engine parts, which is given out to the sump walls due to which separate oil cooler is USED to cool the oil so that lubrication EFFICIENCY is increased.

The correct ANSWER is (a) rifle

The explanation is: A rifle hole is DRILLED from the small end to the big end of the connecting rod through which the LUBRICATING oil flows. This oil present in the small end gains HEAT from the PISTON and reaches the big end of the connecting rod and mixes with the oil present in the oil sump.

The correct choice is (d) 400-500

The best explanation: The pressure range maintained in the dry-sump SYSTEM 400-500kpa. This pressure lubricates the engine components FIRMLY. The pressure is generally MEASURED in KPA instead of the bar.

The CORRECT option is (d) dry-sump system

Explanation: The system used in race cars is the dry-sump system wherein two pumps are used which makes it more COMPLEX and costlier. The scavenge PUMP is installed in the CRANKCASE PORTION. Whereas the pressure pump pumps the oil through the filter to cylinder bearings.

Correct choice is (a) 200-400

Explanation: In a pressure SYSTEM, an oil PUMP takes oil from the wet will through a strainer and delivers it through a filter to the MAIN oil gallery. Pressure RANGE developed in the pressure system engine LUBRICATION is 200-400kpa.

Right option is (a) PRESSURE system

To explain I would SAY: In a two-stroke engine petroil system is USED in which the oil is added with the FUEL into the tank. The fuel evaporates leaving behind the oil and lubricating the moving parts.

The correct choice is (a) loss DUE to evaporation

Explanation: Viscosity is the friction between two surfaces of the liquid. Viscometer is used to determine the viscosity of the LUBRICATING oil. The viscometer is based on the principle that a viscous liquid resist flow, exhibiting a decreasing pressure ALONG the LENGTH of the slit.

Correct choice is (a) Archimedes principle

Explanation: Archimedes’ principle is the most ACCURATE WAY to determine the specific GRAVITY of the LUBRICATING oil. Archimedes principle states that the buoyant force on an object EQUALS the weight of the fluid it displaces. Specific gravity is the ratio of the density of unknown oil to the density of water.

The correct option is (B) EMULSION number

The BEST I can explain: The time in SECONDS required for the constituents to separate from the emulsion is known as steam emulsion number. A good lubricant should possess a low emulsion number. The QUICKER the oil separates from the emulsion, the lower is the steam emulsion number and for most purposes the oil is suitable.

The CORRECT option is (b) A.S.T.M emulsion

Best explanation: The TENDENCY to de-emulsify is quantitatively determined by the A.S.T.M emulsion test. In this, 20ml of oil is taken in the test tube and steam at 100 DEGREES CENTIGRADE is bubbled through it, till the temperature is raised to 90 degrees centigrade.

Correct option is (c) lubricating oil and WATER

For explanation: When lubricating oil mixes thoroughly with water, an intermediate mixture of the two knows as an emulsion. The lesser the emulsification TENDENCY, the better the oil is. A good lubricant should be such that the emulsion is formed, should BREAK off QUICKLY.

Right option is (C) 56

For explanation I would say: 1 mole of POTASSIUM HYDROXIDE is equal to 56.10564 grams. Hence, ONE liter of normal potassium hydroxide contains 56 grams of potassium hydroxide.

Correct ANSWER is (b) 1

For EXPLANATION I would say: The saponification value of an oil is the number of milligrams of potassium hydroxide REQUIRED to saponify completely one gram of the oil. Saponification is a process INVOLVED with SOAPS and oils.

The correct option is (d) POUR point

For EXPLANATION: The pour point is the TEMPERATURE at which a lubricant just CEASES to flow when COOLED under standard conditions. The lower the pour point the better is the lubricant.