Automotive Engine Auxiliary Systems Multiple Choice Questions on “Lubrication and Lubricants – Oil Filters”.
1. What is the size in the micrometer of the wire gauze present in a strainer?
a) 0-20
b) 20-40
c) 40-60
d) 60-80
Answer: c
Clarification: 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.
2. How is the flow of whole oil concerning the filter in a by-pass system of oil filtration?
a) Passes the filter
b) Doesn’t pass the filter
c) Partially passes the filter
d) The oil flow is not related to the filter
Answer: b
Clarification: 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.
3. What is the pressure range in KPa at which the spring-loaded relief valve is incorporated in the filter which bypasses and an emergency supply of unfiltered oil to the bearings?
a) 0-40
b) 40-100
c) 100-300
d) 400-800
Answer: b
Clarification: 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.
4. Which of the following is not a good characteristic of an oil filter?
a) High filtration efficiency
b) Long life
c) Less pressure loss
d) Dirty exhaust fumes
Answer: d
Clarification: 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.
5. On which side of the oil pump is the surface filter installed?
a) Inlet
b) Outlet
c) Transfer
d) Intermediate
Answer: a
Clarification: 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.
6. Which of the following is also known as Edge type oil filter?
a) Stack
b) Plunger
c) Barrel
d) Piston
Answer: a
Clarification: 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.
7. What is the resistance to flow in the range of bar offered by a new filter element?
a) 0-0.1
b) 0.1-0.3
c) 0.3-0.5
d) 0.5-0.7
Answer: c
Clarification: The resistance to flow offered by a new filter element is about 0.3-0.5 bar. However, with the use, the resistance increases due to clogging of the filter element as the time passes by due to accumulation of dirt and other impurities.
8. Which among the following is provided in an edge type oil filter to remove the impurities periodically?
a) Central knob
b) Adjusting screw
c) Relief valve
d) Pilot jet
Answer: a
Clarification: 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.
9. Which is the most commonly used material for filtering in cartridge type oil filter?
a) Wire gauze
b) Copper
c) Cobalt
d) Zinc
Answer: a
Clarification: 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.
10. In what range is the accumulation of impurities increased concerning the operating time in an unfiltered system?
a) Not proportion
b) Proportional
c) Doesn’t depend
d) Has no effect
Answer: b
Clarification: 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.
11. Which of the following is connected to a knob that operated manually helps in removing impurities on the disc peripheries in an edge type oil filter?
a) Brake
b) Clutch
c) Accelerator
d) Shaft
Answer: b
Clarification: 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.
12. What is the range of maximum permissible resistance in a bar in a cartridge type oil filter?
a) 0
b) 1
c) 2
d) 5
Answer: c
Clarification: 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.
13. What is the speed range of the rotor is usually in rpm in a centrifugal type oil filter?
a) 0-1000
b) 1000-2000
c) 2000-7000
D) 7000-10000
Answer: c
Clarification: The working speed of the rotor in a centrifugal type oil filter is in the range of 2000-7000 rpm, depending upon the oil pressure circulating the oil. Force up to 2000 times the gravity is produced which are quite effective in throwing the impurities.