This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers (MCQs) focuses on “Testing of Lubricants”
1. ______ apparatus is used in the determination of Flash and Fire point of a lubricating oil.
a) saybolt
b) engler
c) able’s
d) redwood
View Answer
Explanation: Flashpoint is the minimum temperature at which it gives vapor which is sufficient to form an explosive mixture with air. The fire point is the further heating to a stage where it starts to burn continuously on applying flame to it. Both are determined by Abel’s apparatus.
2. ______ apparatus is used in the determination of loss due to Evaporation of the lubricating oil.
a) able’s
b) engler
c) arch butt
d) hydrometer
View Answer
Explanation: When the lubricating oil is subjected to high temperatures, they are liable to vaporize to a certain extent. Loss due to evaporation of the lubricating oil is determined by the Arch butt method.
3. ______ is the temperature at which lubricating oil ceases to flow when cooled at standard condition.
a) flashpoint
b) fire point
c) moisture test
d) pour point
View Answer
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.
4. The acid value of an oil is the number of milligrams of ______ used to neutralize 1gram of oil.
a) sodium hydroxide
b) potassium hydroxide
c) sulfur dioxide
d) ester
View Answer
Explanation: Acid value of an oil is the number of milligrams of potassium hydroxide required to neutralize 1gram of oil. To determine the acid value, about 5-10 grams of the oil is taken in a conical flask. About 40-50 c.c of neutral alcohol is added in the flask.
5. Saponification value of an oil is the number of milligrams of potassium hydroxide required to saponify completely ______ grams of the oil.
a) 10
b) 1
c) 1000
d) 100
View Answer
Explanation: 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.
6. Determination of saponification value helps in the detection of ______
a) acid
b) base
c) salt
d) adulteration
View Answer
Explanation: Saponification value refers to the small amounts of compounds containing oxygen, which are not removed during the refining process and this value also helps in the detection of adulteration.
7. One liter of normal potassium hydroxide contains ______grams of potassium hydroxide.
a) 65
b) 67
c) 56
d) 59
View Answer
Explanation: 1 mole of potassium hydroxide is equal to 56.10564 grams. Hence, One liter of normal potassium hydroxide contains 56 grams of potassium hydroxide.
8. Emulsion is a mixture of ______and ______when mixed thoroughly.
a) lubricating oil and acid
b) water and acid
c) lubricating oil and water
d) lubricating oil and base
View Answer
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.
9. Insoluble residue test is used to determine______
a) additives
b) insoluble particles
c) pour point
d) fire point
View Answer
Explanation: A known weight of the lubricating oil is dissolved in spirit .the solution is filtered and the residue is washed with pure solvent, dried, and weighed. From this percentage of insoluble residue in the oil is calculated.
10. The tendency to de-emulsify quantitatively is determined by ______test.
a) hydrometer
b) A.S.T.M emulsion
c) centistokes
d) centipoises
View Answer
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.
11. The time required for the constituents to separate from the emulsion is known as ______
a) saponification number
b) emulsion number
c) Archimedes principle
d) acid value test
View Answer
Explanation: 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.
12. Specific gravity is determined by ______ test.
a) Archimedes principle
b) acid value test
c) emulsification test
d) insoluble residue test
View Answer
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.
13. ______ is used to find the viscosity of the lubricating oil.
a) loss due to evaporation
b) viscometer
c) moisture test
d) None
View Answer
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.
Sanfoundry Global Education & Learning Series – Automotive Engine Auxiliary Systems.
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