172 + Interview Questions in Lubricants in Applied Chemistry Page 2 InterviewSolution

51.	High mechanical stability is more for ________(a) sodium base greases(b) lithium soap greases(c) complex greases(d) cup greasesI got this question in final exam.My query is from Classification of Lubricants in portion Lubricants of Applied Chemistry
Answer» Correct choice is (B) LITHIUM soap greases To explain I would say: About 65% of the market is captured by the lithium greases. They have high mechanical STABILITY. They are also stable for STORAGE. They are expensive and USED for specific applications like in air crafts.

Discussion

52.	Rate of oxidation in petroleum oil proceeds _________ at room temperature.(a) Slowly(b) Fast(c) Moderate(d) ConstantThe question was asked in quiz.The above asked question is from Oxidation Stability and Aniline Number in division Lubricants of Applied Chemistry
Answer» The correct answer is (a) SLOWLY Easiest EXPLANATION: RATE of the OXIDATION in petroleum oil proceeds slowly at room temperature. It proceeds faster at elevated temperature. Elevated temperature MEANS above 200^oC.

Discussion

53.	The kinematic viscosity of the oil can be calculated by ___________(a) V = ŋ+ρ(b) V = ŋ/ρ(c) V = ŋ – ρ(d) V = ŋ*ρI had been asked this question in unit test.My question is based upon Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry
Answer» Right answer is (b) V = ŋ/ρ For EXPLANATION: The kinematic viscosity means the viscosity that determines the kinematic ENERGY of the LIQUID that means it determines the speed of the oil. So, the kinematic viscosity of the oil is GIVEN by V=ŋ/ρ, where ŋ = ABSOLUTE viscosity of the oil and ρ = density of the oil.

Discussion

54.	The saponification value of the hard oil is _________(a) 192-198(b) 194-195(c) 194-196(d) 190-191This question was posed to me in quiz.My enquiry is from Saponification Value topic in chapter Lubricants of Applied Chemistry
Answer» CORRECT OPTION is (a) 192-198 For explanation I would say: The SAPONIFICATION value of the hard OIL is 192-198. Though it has no acid value it has saponification value. 194-195 is the saponification value of the cotton seed oil. Groundnut oil and WHALE oil has the saponification values of 194-196 and 190-191 respectively.

Discussion

55.	The saponification value is given by ______(a) Saponification value = (volume of KOH +NKOH+56)/wt of the oil taken(b) Saponification value = (volume of KOH * NKOH/56)/wt of the oil taken(c) Saponification value = (volume of KOH * NKOH*56)/wt of the oil taken(d) Saponification value = (volume of KOH – NKOH-56)/wt of the oil takenI have been asked this question by my school principal while I was bunking the class.This intriguing question originated from Saponification Value topic in division Lubricants of Applied Chemistry
Answer» Correct CHOICE is (c) Saponification value = (volume of KOH * NKOH56)/WT of the oil TAKEN The explanation: The saponification value is given by Saponification value = (volume of KOH NKOH*56)/wt of the oil taken. So, to determine the saponification value FIRST we NEED to know the volume of KOH utilised.

Discussion

56.	Which of the following is not the inorganic lubricant?(a) WS2(b) TiTe2(c) GaS(d) PbI have been asked this question by my school teacher while I was bunking the class.This interesting question is from Classification of Lubricants in division Lubricants of Applied Chemistry
Answer» The CORRECT CHOICE is (d) Pb Easy EXPLANATION: Pb is the soft metal lubricant. Sulphides, selenides and telluride’s of MOLYBDENUM, tungsten, niobium, tantalum and titanium are COMES under the inorganic lubricants.

Discussion

57.	It is __________ of fatty oils which leads to formation of soaps.(a) Alkaline hydrolysis(b) Alkaline electrolysis(c) Hydrolysis(d) ElectrolysisThis question was posed to me in homework.Enquiry is from Saponification Value topic in chapter Lubricants of Applied Chemistry
Answer» The correct choice is (a) Alkaline hydrolysis Easiest EXPLANATION: It is alkaline hydrolysis of fatty oils which leads to FORMATION of soaps. As the fatty materials are present in the oil, that oil on saponification that MEANS on alkaline hydrolysis GIVES the soaps as product.

Discussion

58.	The total acid number of an oil is given by __________(a) Acid value = (volume of 0.1N KOH taken56)/(weight of oil used)(b) Acid value = (volume of 0.01N KOH used56)/(weight of oil taken)(c) Acid value = (volume of 0.1N KOH used56)/(weight of oil taken)(d) Acid value = (volume of 0.01N KOH taken56)/(weight of oil used)The question was posed to me by my college director while I was bunking the class.This intriguing question originated from Neutralization/Acidic Number in chapter Lubricants of Applied Chemistry
Answer» Correct CHOICE is (c) Acid value = (volume of 0.1N KOH USED56)/(WEIGHT of oil taken) For explanation: The total acid number of an oil is given by Acid value= (volume of 0.1N KOH used56)/(weight of oil taken), where the 0.1 is the MAXIMUM value of the oil and 56 is the molecular weight of the KOH.

Discussion

59.	The wear and tear of metal surfaces are involved and _________ are formed in thin lubrication.(a) P-n junctions(b) Welded junctions(c) Layers(d) Thin layersI had been asked this question in unit test.This interesting question is from Mechanism of Lubrication topic in chapter Lubricants of Applied Chemistry
Answer» Right choice is (B) Welded junctions The best EXPLANATION: The wear and tear of the metal surfaces is involved and the welded junctions are FORMED. This also RESULTS in friction. These all are formed due to the contact of the surfaces with other leads.

Discussion

60.	Foaming of oils can be prevented by using ___________(a) Despersants(b) Foam inhibitors(c) Rust inhibitors(d) Oxide inhibitorsThe question was asked during an interview for a job.The doubt is from Types of Additives in chapter Lubricants of Applied Chemistry
Answer» RIGHT answer is (b) Foam inhibitors The EXPLANATION is: Foam inhibitors are used for preventing the foaming of oil in internal combustion engines. Methyl silicone POLYMERS are used as effective foam inhibitors.they are not SOLUBLE in oil they help in BREAKING form bubbles.

Discussion

61.	Petrol captured the market up to the percentage of _________(a) 100%(b) 90%(c) 98%(d) 75%This question was addressed to me in an online quiz.I'm obligated to ask this question of Classification of Lubricants in division Lubricants of Applied Chemistry
Answer» Correct ANSWER is (c) 98% Explanation: Petrol CAPTURED 98% of the market. Naphthenes and PARAFFIN compounds are MAINLY found in mineral oils and they are more efficient in preventing the metals from corrosion.

Discussion

62.	The lubricants used in refrigerators will have ________(a) no pour point(b) high viscosity(c) high pour point(d) low cloud pointThis question was addressed to me at a job interview.This key question is from Selection of Lubricants topic in division Lubricants of Applied Chemistry
Answer» Right choice is (d) LOW CLOUD point The best explanation: Generally, NAPTHALENE and base oils are used as LUBRICATING oils in the REFRIGERATORS. They must have the low cloud point, low pour point and low viscosity.

Discussion

63.	The lubricants for transformers must have quality of good ________(a) dielectric strength(b) less oiliness(c) no resistance to oxygen(d) low load capacityI have been asked this question during a job interview.My query is from Selection of Lubricants topic in portion Lubricants of Applied Chemistry
Answer» The correct choice is (a) dielectric strength The BEST I can explain: The DI electric must be good for the transformers. They are DRIED, WASHED and FILTERED properly and applied with lubricants.

Discussion

64.	For, delicate instruments the suitable lubricants are _________(a) light cutting oil(b) sunflower oil(c) heavy cutting oil(d) thin vegetable oilThis question was posed to me during an online interview.I'd like to ask this question from Selection of Lubricants topic in chapter Lubricants of Applied Chemistry
Answer» Right option is (d) THIN vegetable oil To explain I WOULD say: For DELICATE instruments, suitable LUBRICANTS are very soft ones. They may be like thin vegetable oil, PALM oil etc.

Discussion

65.	For heavy cutting, the effective lubricants are _________(a) coconut oils(b) cutting oils(c) kerosene(d) dieselThis question was addressed to me during an interview for a job.This interesting question is from Selection of Lubricants in portion Lubricants of Applied Chemistry
Answer» Correct answer is (b) cutting oils The best explanation: The cutting oils are most SUITABLE oils for HEAVY cutting. The lubricants CONTAIN the ADDITIVES like fatty oils and sulphurized fatty oils and CHLORINATED compounds.

Discussion

66.	The cloud point is the index of the ___________ temperature.(a) Lowest(b) Highest(c) Reference(d) InfinityI got this question by my college professor while I was bunking the class.This intriguing question originated from Cloud Point and Pour Point in section Lubricants of Applied Chemistry
Answer» Correct OPTION is (a) LOWEST Easiest explanation: The cloud point is the index of the lowest TEMPERATURE of its utility for CERTAIN APPLICATIONS. Every lubricating oil has cloud point in most of cases it is true.

Discussion

67.	For refrigerator system, the oils with the low viscosity, high cloud point and low pour point are used.(a) True(b) FalseI got this question in a job interview.I'd like to ask this question from Lubricants General Questions in portion Lubricants of Applied Chemistry
Answer» RIGHT answer is (b) False Best explanation: For REFRIGERATOR SYSTEM, the oils with low viscosity, low cloud POINT and low pour point are used. MOSTLY, these characteristics are seen in naphthalene-base oils. So, they are used for these purposes.

Discussion

68.	The lubricating oil is volatilises then the formed vapour __________(a) Must be less(b) Must be high(c) Non-inflammable(d) FlammableI had been asked this question during an interview for a job.This intriguing question originated from Lubricants General Questions in portion Lubricants of Applied Chemistry
Answer» Correct answer is (c) Non-inflammable The explanation is: MANY times the LUBRICANT in use must FACE the high temperatures. The good lubricating oil must not VOLATILISES even if volatilises its vapours should not catch the FIRE.

Discussion

69.	The jet is opened or closed by ___________(a) Cup(b) Valve rod(c) Stout wire(d) ScrewThis question was posed to me by my college professor while I was bunking the class.Asked question is from Viscosity and Viscosity Index topic in section Lubricants of Applied Chemistry
Answer» CORRECT answer is (B) Valve rod Best explanation: The jet of the redwood viscometer is OPENED or CLOSE by using the valve rod. The lid of the cup is provided with the spirit level for the vertical LEVELLING of the jet.

Discussion

70.	Periodic determination of acid number is useful to indicate the progress of ________(a) Oxidation number(b) Reduction number(c) Acidic number(d) Neutralisation numberI had been asked this question in an internship interview.The doubt is from Neutralization/Acidic Number in portion Lubricants of Applied Chemistry
Answer» Correct option is (a) Oxidation NUMBER Easy explanation: The periodic determination of the acid number is USEFUL to INDICATE the PROGRESS of oxidation number. The age of the oil is determined by the increase in acid number with time due to HYDROLYSIS with moisture.

Discussion

71.	The oil cup is made up of _________(a) Brass(b) Copper(c) Silver(d) ChromiumThis question was posed to me by my school principal while I was bunking the class.I would like to ask this question from Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry
Answer» Right option is (a) Brass The explanation is: The OIL cup is one of the parts of the REDWOOD viscometer. It is made up of brass. It is OPEN at upper end. Its base is fitted with an AGATE jet, with the bore of diameter 1.62mm and internal length 10mm.

Discussion

72.	Test thermometer is one of the parts of the redwood viscometer.(a) True(b) FalseI got this question during an interview.Question is taken from Viscosity and Viscosity Index topic in division Lubricants of Applied Chemistry
Answer» Correct answer is (a) True Best explanation: The parts of the REDWOOD viscometer are TEST thermometer, BATH thermometer, water inlet, oil STIRRER, water bath, heating coil, metal indicator, brass oil cup, water bath stirrer BLADE, valve rod, water outlet, agate jet, kohlrausch flask and levelling screw.

Discussion

73.	The viscosity of the lubricating oil must be sufficient to keep it in position.(a) True(b) FalseThe question was asked by my school teacher while I was bunking the class.This key question is from Viscosity and Viscosity Index topic in portion Lubricants of Applied Chemistry
Answer» Correct option is (a) True For explanation: The viscosity of the lubricating must not be low. It ALSO should not be too high. If it is too high then the liquid FLOW more faster and causes high or EXCESSIVE friction. If it is low then the liquid moves very SLOWLY and have low friction. SUFFICIENT viscosity should be there to keep a liquid in a position.

Discussion

74.	The oxidation inhibitors terminate the hydro peroxide chain by combining with ___________(a) Hydrogen peroxide(b) Oxides of metals(c) Hydro carbons(d) OzoneThis question was posed to me during a job interview.The doubt is from Types of Additives topic in division Lubricants of Applied Chemistry
Answer» Correct option is (a) HYDROGEN peroxide The BEST explanation: After the homolytic fission of the petroleum oil to produce free radicals and they REACT with oxides to form the hydrogen peroxides. Some HYDRO peroxides decompose to form the aldehydes, ketones etc. If they are reacted with hydrogen peroxide then the CHAIN will be terminated.

Discussion

75.	Calcium complex grease can be made from ___________(a) lime, fatty acid, acetic acid(b) calcium, lime, acetic acid(c) calcium, lime, acetic acid(d) lime, calcium, acetic acidThe question was asked in an internship interview.Question is taken from Classification of Lubricants topic in division Lubricants of Applied Chemistry
Answer» CORRECT option is (a) lime, FATTY acid, ACETIC acid Easiest explanation: Calcium complex grease is formed out of the lime, fatty acid and acetic acid. The grease can be formed by USING the sodium, ALUMINIUM and lithium. That is why these lubricants have high melting points.

Discussion

76.	The lowest temperature at which the oils gives enough vapour.(a) Pour point(b) Cloud point(c) Flash point(d) Fire pointThe question was posed to me in examination.Question is taken from Lubricants General Questions topic in division Lubricants of Applied Chemistry
Answer» The correct choice is (c) Flash point The EXPLANATION is: The LOWEST temperature at which the oil gives the enough vapour is flash point. Cloud point is the temperature expressed in MULTIPLES of 1^oC at which the HAZE of the wax crystal appears when the oil is cooled under prescribed conditions.

Discussion

77.	The long side tube is used to heat the water by means of ________(a) Burner(b) Spirit lamp(c) Bunsen burner(d) CandleThis question was posed to me in my homework.The query is from Viscosity and Viscosity Index topic in division Lubricants of Applied Chemistry
Answer» Right CHOICE is (B) Spirit lamp Best explanation: The LONG side tube is projected outwards. This is used to heat the water by MEANS of GAS or spirit lamp. The copper vessel is provided with thermometer to measure the temperature of the water.

Discussion

78.	Lubricating oil having low aniline point results in _________(a) Deterioration of metal(b) Deterioration of rubber(c) Deterioration of wall of jar(d) Deterioration of ironI had been asked this question in an interview for internship.This intriguing question originated from Oxidation Stability and Aniline Number in division Lubricants of Applied Chemistry
Answer» Correct answer is (b) Deterioration of rubber The best I can EXPLAIN: The lubricating OIL with low aniline POINT will tend to attack the rubber parts and results in deterioration of rubber and leakage MAY takes PLACE.

Discussion

79.	Aniline number is the minimum equilibrium solution temperature for ________ volume of aniline and lubricating oil.(a) More(b) Less(c) Equal(d) Very highThis question was posed to me in final exam.I'd like to ask this question from Oxidation Stability and Aniline Number in section Lubricants of Applied Chemistry
Answer» The CORRECT option is (c) Equal The explanation: Aniline NUMBER is the minimum equilibrium solution temperature for equal VOLUME of aniline and lubricating oil. The equal volume is TAKEN then only it is known as aniline number.

Discussion

80.	For machines operating at the high speed and low pressure __________ are used.(a) Heavy oils(b) Light oils(c) Crude oils(d) Diesel oilThis question was addressed to me at a job interview.This intriguing question originated from Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry
Answer» The correct option is (B) Light oils The EXPLANATION is: For machines operating at the high speed and low pressure, the lubricating OIL use is light oil. The light oil do not impose as much drag on high speed parts. THEREFORE, for the minimum friction, the thinner oil STAYS at position.

Discussion

81.	The most common reason for the degradation of petroleum oil is their _________(a) Volatility(b) Oxidation(c) Reduction(d) Temperature coefficientThe question was asked in final exam.The doubt is from Types of Additives topic in portion Lubricants of Applied Chemistry
Answer» Right answer is (b) Oxidation Best explanation: Oxidation inhibitors are one of the types of the ADDITIVES. The oxidation is the MAIN reason for the petroleum oil DEGRADATION. At high temperatures, the hydro CARBONS of the petroleum oil undergo homolytic fission to generate free radicals.

Discussion

82.	The emulsifiers in water in oil type emulsions are ________(a) Sodium salts(b) Potassium salts(c) Oxides(d) Alkaline earth soapsThe question was asked in examination.My query is from Classification of Lubricants in chapter Lubricants of Applied Chemistry
Answer» The CORRECT CHOICE is (d) Alkaline earth soaps Easy explanation: The EMULSIFIERS in water in oil type are alkaline earth metals. Sulphides, sodium and POTASSIUM SALTS are used in oil in water type emulsion. To prepare water in oil type emulsions, 1-10% of water and emulsifiers are added to the oil.

Discussion

83.	Which of the following is not the liquid lubricant?(a) Olive oil(b) Palm oil(c) Castor oil(d) GreaseThe question was posed to me during an online interview.Origin of the question is Classification of Lubricants in chapter Lubricants of Applied Chemistry
Answer» RIGHT option is (d) Grease Best explanation: Grease is the semi-solid lubricant which has high VISCOSITY but the liquid lubricant must have an adequate amount of viscosity. It should not be more or LESS. Olive oil, PALM oil, CASTOR oil are liquid lubricants.

Discussion

84.	Sodium base greases can be utilized up to the temperature of ____________(a) 175^oC(b) 100^oC(c) 75^oC(d) 80^oCI had been asked this question in an online interview.I would like to ask this question from Classification of Lubricants topic in chapter Lubricants of Applied Chemistry
Answer» CORRECT choice is (a) 175^oC For EXPLANATION: Sodium soaps are soluble in WATER and they are not water resistant. As they are not stabilized with water. They can resist up to a temperature of 175^oC. They can be used at ball and roller BEARING at which there will be heat production DUE to heat.

Discussion

85.	The neutralisation number is increased due to _________(a) Pureness(b) Contamination(c) Hydrolysis(d) CatalysisThis question was addressed to me in quiz.I'm obligated to ask this question of Neutralization/Acidic Number in section Lubricants of Applied Chemistry
Answer» Correct option is (B) Contamination For explanation I would say: The neutralisation number is increased DUE to the contamination as the oil is used. Examples are SULPHUR dioxide on combustion of sulphur, carbondioxide on combustion of carbon or present in the ATMOSPHERE.

Discussion

86.	Pour point indicates the _______ of lubricating oil.(a) Dissolved wax concentration(b) Total wax concentration(c) Initial wax concentration(d) Weight of the waxI had been asked this question in my homework.The question is from Cloud Point and Pour Point topic in portion Lubricants of Applied Chemistry
Answer» CORRECT choice is (a) Dissolved wax concentration To explain I would say: Pour POINT indicates the dissolved wax concentration of lubricating oil. In pour point EXPERIMENT two thermometers are present to measure the temperature off COOLING mixture and lubricating oil.

Discussion

87.	The height and diameter of the oil cup is __________ respectively.(a) 250mm, 46.5mm(b) 290mm, 46.5mm(c) 290mm, 40.5mm(d) 250mm, 40.5mmThe question was asked during an interview for a job.My question is taken from Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry
Answer» The CORRECT choice is (B) 290mm, 46.5mm For explanation I would SAY: The height of the oil cup is 290mm and the diameter is about 46.5mm. The level to which the oil cup is fixed with oil is indicated by the stout wire fixed in the side of the oil cup. The wire is turned upwards and it is TAPERED to sharp point to indicate level PROPERLY.

Discussion

88.	The coefficient of friction of unlubricated surface ranges about _________(a) 0.1-1.5(b) 0.1-0.5(c) 0.1-1.0(d) 1.5-2.0I had been asked this question in my homework.This interesting question is from Mechanism of Lubrication in division Lubricants of Applied Chemistry
Answer» The correct option is (a) 0.1-1.5 Easiest explanation: The coefficient of the UNLUBRICATED surface is about 0.1 to 1.5. If the lubricant energy is higher, then the energy MUST be REQUIRED in large amount to circulate and maintain the VISCOUS lubricant film.

Discussion

89.	Easily oxidised impurities cause ___________(a) Moisture formation(b) Nitrogen formation(c) Sludge formation(d) Ash formationThe question was asked in an online interview.This question is from Classification of Lubricants topic in section Lubricants of Applied Chemistry
Answer» Right choice is (c) Sludge FORMATION Easiest EXPLANATION: The easily oxidisable impurities cause the sludge formation. During the OPERATING CONDITIONS, the asphaltic. Napthatic compounds will allows to form the sludge. As they decompose at high temperatures to cause the formation of carbon also.

Discussion

90.	The lubricating oils must be refined to remove ___________(a) Wax(b) Hydrocarbons(c) Nitrogen(d) OxygenThis question was addressed to me in semester exam.This intriguing question comes from Classification of Lubricants in division Lubricants of Applied Chemistry
Answer» The CORRECT choice is (a) Wax The EXPLANATION is: The lubricating oils must be refined to remove the COMPOUNDS like wax, aromatic compounds and ASPHALTIC compound. If these compounds are not REMOVED then they will be crystallize and stops the flow of lubricating oil.

Discussion

91.	Soft metals possess lubrication due to ___________(a) low plasticity(b) high plasticity(c) no plasticity(d) moderate plasticityI have been asked this question in quiz.This intriguing question originated from Classification of Lubricants in portion Lubricants of Applied Chemistry
Answer» CORRECT answer is (b) high plasticity The explanation: The SOFT metals have the high plasticity as they have low shear strength. Lead, tin, BISMUTH, indium, CADMIUM and silver are the some of the EXAMPLES of soft metal lubricants.

Discussion

92.	One of the advantages of the solid lubricants is ___________(a) unstable in radiation(b) high coefficient of friction than liquid lubricants(c) low coefficient of friction(d) permit equipment is simpleThe question was asked in unit test.Origin of the question is Classification of Lubricants topic in chapter Lubricants of Applied Chemistry
Answer» The CORRECT option is (d) permit equipment is simple To explain: The permit equipment is simple so that it can be CARRIED ANYWHERE very easily. Normally, the coefficient of friction of the solid lubricant is LOW and it is a disadvantage. Another disadvantage is it is unstable in radiation.

Discussion

93.	The location of the cup in air bath can be known using __________(a) Flange(b) Leaver(c) Shutter(d) Pilot burnerI have been asked this question in final exam.This interesting question is from Lubricants General Questions topic in section Lubricants of Applied Chemistry
Answer» Right CHOICE is (a) Flange Best explanation: The location of the cup in air bath can be known USING the flange. The cup is SUPPORTED by a flange over HEATING vessel such a way that there is CLEARANCE between them.

Discussion

94.	If the oxidation product is soluble then it is desirable for lubricants.(a) True(b) FalseI got this question in an internship interview.The origin of the question is Oxidation Stability and Aniline Number in portion Lubricants of Applied Chemistry
Answer» The correct choice is (b) False To explain I would say: If the OXIDATION product is SOLUBLE in the lubricating oil, then also it is not DESIRABLE because it circulates with the oil and may corrode or pit bearing surfaces and may FORM vanish like DEPOSITS and gums.

Discussion

95.	The temperature expressed in multiples of 1^oC at which the haze of the wax crystal appears when the oil is cooled under prescribed conditions is called ________(a) Pour point(b) Cloud point(c) Oxidation stability(d) Acid numberThis question was addressed to me in homework.I need to ask this question from Cloud Point and Pour Point topic in section Lubricants of Applied Chemistry
Answer» CORRECT choice is (b) Cloud point The explanation: The TEMPERATURE expressed in MULTIPLES of 1^oC at which the haze of the wax crystal APPEARS when the oil is cooled under PRESCRIBED conditions is called cloud point. The haze of wax crystals is also called as cloud. It appears on the walls of the jar.

Discussion

96.	Gear oils on adding viscosity index improves can be used in ___________(a) Motor vehicles(b) Machinery(c) Air crafts(d) EnginesI got this question in a job interview.Origin of the question is Types of Additives in portion Lubricants of Applied Chemistry
Answer» The correct option is (C) Air crafts For explanation: Gear OILS on improving the VISCOSITY, they can be used in air crafts. There are some other materials that can be used in air crafts by increasing their viscosity are multi GRADE automotive engine oils and automatic TRANSMISSION oils.

Discussion

97.	Complex grease fibers are formed by reacting two dissimilar ___________ with single _________(a) base, alkali(b) alkali, acids(c) alkali, base(d) acids, alkaliThis question was posed to me in final exam.This interesting question is from Classification of Lubricants topic in portion Lubricants of Applied Chemistry
Answer» The CORRECT CHOICE is (d) acids, ALKALI For explanation I would say: Complex grease fibers are formed by reacting TWO dissimilar acids with single alkali that are used as thickener in many of the commercial complex greases. Additives like anti-oxidants, corrosion INHIBITORS and extreme pressure additives are added to the greases.

Discussion

98.	The commonly used dispersant is _____________(a) Carboxylic acid(b) Alkyl phosphoric acid(c) Poly butyl succinic acid(d) Sodium salts of alkyl benzene sulfonic acidI have been asked this question in an internship interview.My question comes from Types of Additives topic in portion Lubricants of Applied Chemistry
Answer» Right choice is (C) Poly butyl succinic ACID For explanation I would say: The calcium, sodium and magnesium SALTS of the alkyl benzene sulfonic acids are used as detergents. CARBOXYLIC aids and the alkyl phosphoric acid are the other commonly used detergents. The commonly used despersants is poly butyl succinic acid.

Discussion

99.	To improve the refined petroleum oils ___________ are added.(a) Additives(b) Inhibitors(c) Catalysts(d) CarbonThis question was posed to me during a job interview.My question is based upon Classification of Lubricants in section Lubricants of Applied Chemistry
Answer» Correct CHOICE is (a) Additives Easy explanation: Additives are added to REFINED PETROLEUM OILS. They are refined by processes LIKE dewaxing etc. They are added to improve the performance of the lubricants. They are called as blended oils as additives are added.

Discussion

100.	What is the range of coefficient of friction for solid lubricants?(a) 0.005-0.01(b) 0.001-0.01(c) 0.0001-0.001(d) 0.0005-0.001This question was addressed to me during an interview for a job.The query is from Classification of Lubricants in chapter Lubricants of Applied Chemistry
Answer» Right option is (a) 0.005-0.01 For explanation I would SAY: The range of the COEFFICIENT of friction for solid lubricants is very less that of 0.005-0.01. This must be low for effective lubrication because the lubricant is mainly used to CONTROL the friction between the machine PARTS.

Discussion

Explore topic-wise InterviewSolutions in .

High mechanical stability is more for ________(a) sodium base greases(b) lithium soap greases(c) complex greases(d) cup greasesI got this question in final exam.My query is from Classification of Lubricants in portion Lubricants of Applied Chemistry

Rate of oxidation in petroleum oil proceeds _________ at room temperature.(a) Slowly(b) Fast(c) Moderate(d) ConstantThe question was asked in quiz.The above asked question is from Oxidation Stability and Aniline Number in division Lubricants of Applied Chemistry

The kinematic viscosity of the oil can be calculated by ___________(a) V = ŋ+ρ(b) V = ŋ/ρ(c) V = ŋ – ρ(d) V = ŋ*ρI had been asked this question in unit test.My question is based upon Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry

The saponification value of the hard oil is _________(a) 192-198(b) 194-195(c) 194-196(d) 190-191This question was posed to me in quiz.My enquiry is from Saponification Value topic in chapter Lubricants of Applied Chemistry

Which of the following is not the inorganic lubricant?(a) WS2(b) TiTe2(c) GaS(d) PbI have been asked this question by my school teacher while I was bunking the class.This interesting question is from Classification of Lubricants in division Lubricants of Applied Chemistry

It is __________ of fatty oils which leads to formation of soaps.(a) Alkaline hydrolysis(b) Alkaline electrolysis(c) Hydrolysis(d) ElectrolysisThis question was posed to me in homework.Enquiry is from Saponification Value topic in chapter Lubricants of Applied Chemistry

Foaming of oils can be prevented by using ___________(a) Despersants(b) Foam inhibitors(c) Rust inhibitors(d) Oxide inhibitorsThe question was asked during an interview for a job.The doubt is from Types of Additives in chapter Lubricants of Applied Chemistry

Petrol captured the market up to the percentage of _________(a) 100%(b) 90%(c) 98%(d) 75%This question was addressed to me in an online quiz.I'm obligated to ask this question of Classification of Lubricants in division Lubricants of Applied Chemistry

The lubricants used in refrigerators will have ________(a) no pour point(b) high viscosity(c) high pour point(d) low cloud pointThis question was addressed to me at a job interview.This key question is from Selection of Lubricants topic in division Lubricants of Applied Chemistry

The lubricants for transformers must have quality of good ________(a) dielectric strength(b) less oiliness(c) no resistance to oxygen(d) low load capacityI have been asked this question during a job interview.My query is from Selection of Lubricants topic in portion Lubricants of Applied Chemistry

For heavy cutting, the effective lubricants are _________(a) coconut oils(b) cutting oils(c) kerosene(d) dieselThis question was addressed to me during an interview for a job.This interesting question is from Selection of Lubricants in portion Lubricants of Applied Chemistry

The cloud point is the index of the ___________ temperature.(a) Lowest(b) Highest(c) Reference(d) InfinityI got this question by my college professor while I was bunking the class.This intriguing question originated from Cloud Point and Pour Point in section Lubricants of Applied Chemistry

For refrigerator system, the oils with the low viscosity, high cloud point and low pour point are used.(a) True(b) FalseI got this question in a job interview.I'd like to ask this question from Lubricants General Questions in portion Lubricants of Applied Chemistry

The jet is opened or closed by ___________(a) Cup(b) Valve rod(c) Stout wire(d) ScrewThis question was posed to me by my college professor while I was bunking the class.Asked question is from Viscosity and Viscosity Index topic in section Lubricants of Applied Chemistry

The oil cup is made up of _________(a) Brass(b) Copper(c) Silver(d) ChromiumThis question was posed to me by my school principal while I was bunking the class.I would like to ask this question from Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry

Test thermometer is one of the parts of the redwood viscometer.(a) True(b) FalseI got this question during an interview.Question is taken from Viscosity and Viscosity Index topic in division Lubricants of Applied Chemistry

The viscosity of the lubricating oil must be sufficient to keep it in position.(a) True(b) FalseThe question was asked by my school teacher while I was bunking the class.This key question is from Viscosity and Viscosity Index topic in portion Lubricants of Applied Chemistry

The oxidation inhibitors terminate the hydro peroxide chain by combining with ___________(a) Hydrogen peroxide(b) Oxides of metals(c) Hydro carbons(d) OzoneThis question was posed to me during a job interview.The doubt is from Types of Additives topic in division Lubricants of Applied Chemistry

The lowest temperature at which the oils gives enough vapour.(a) Pour point(b) Cloud point(c) Flash point(d) Fire pointThe question was posed to me in examination.Question is taken from Lubricants General Questions topic in division Lubricants of Applied Chemistry

The long side tube is used to heat the water by means of ________(a) Burner(b) Spirit lamp(c) Bunsen burner(d) CandleThis question was posed to me in my homework.The query is from Viscosity and Viscosity Index topic in division Lubricants of Applied Chemistry

The most common reason for the degradation of petroleum oil is their _________(a) Volatility(b) Oxidation(c) Reduction(d) Temperature coefficientThe question was asked in final exam.The doubt is from Types of Additives topic in portion Lubricants of Applied Chemistry

The emulsifiers in water in oil type emulsions are ________(a) Sodium salts(b) Potassium salts(c) Oxides(d) Alkaline earth soapsThe question was asked in examination.My query is from Classification of Lubricants in chapter Lubricants of Applied Chemistry

Which of the following is not the liquid lubricant?(a) Olive oil(b) Palm oil(c) Castor oil(d) GreaseThe question was posed to me during an online interview.Origin of the question is Classification of Lubricants in chapter Lubricants of Applied Chemistry

Sodium base greases can be utilized up to the temperature of ____________(a) 175^oC(b) 100^oC(c) 75^oC(d) 80^oCI had been asked this question in an online interview.I would like to ask this question from Classification of Lubricants topic in chapter Lubricants of Applied Chemistry

The neutralisation number is increased due to _________(a) Pureness(b) Contamination(c) Hydrolysis(d) CatalysisThis question was addressed to me in quiz.I'm obligated to ask this question of Neutralization/Acidic Number in section Lubricants of Applied Chemistry

The height and diameter of the oil cup is __________ respectively.(a) 250mm, 46.5mm(b) 290mm, 46.5mm(c) 290mm, 40.5mm(d) 250mm, 40.5mmThe question was asked during an interview for a job.My question is taken from Viscosity and Viscosity Index topic in chapter Lubricants of Applied Chemistry

The coefficient of friction of unlubricated surface ranges about _________(a) 0.1-1.5(b) 0.1-0.5(c) 0.1-1.0(d) 1.5-2.0I had been asked this question in my homework.This interesting question is from Mechanism of Lubrication in division Lubricants of Applied Chemistry

Easily oxidised impurities cause ___________(a) Moisture formation(b) Nitrogen formation(c) Sludge formation(d) Ash formationThe question was asked in an online interview.This question is from Classification of Lubricants topic in section Lubricants of Applied Chemistry

The lubricating oils must be refined to remove ___________(a) Wax(b) Hydrocarbons(c) Nitrogen(d) OxygenThis question was addressed to me in semester exam.This intriguing question comes from Classification of Lubricants in division Lubricants of Applied Chemistry

Soft metals possess lubrication due to ___________(a) low plasticity(b) high plasticity(c) no plasticity(d) moderate plasticityI have been asked this question in quiz.This intriguing question originated from Classification of Lubricants in portion Lubricants of Applied Chemistry

The location of the cup in air bath can be known using __________(a) Flange(b) Leaver(c) Shutter(d) Pilot burnerI have been asked this question in final exam.This interesting question is from Lubricants General Questions topic in section Lubricants of Applied Chemistry

If the oxidation product is soluble then it is desirable for lubricants.(a) True(b) FalseI got this question in an internship interview.The origin of the question is Oxidation Stability and Aniline Number in portion Lubricants of Applied Chemistry

Gear oils on adding viscosity index improves can be used in ___________(a) Motor vehicles(b) Machinery(c) Air crafts(d) EnginesI got this question in a job interview.Origin of the question is Types of Additives in portion Lubricants of Applied Chemistry

Complex grease fibers are formed by reacting two dissimilar ___ with single _(a) base, alkali(b) alkali, acids(c) alkali, base(d) acids, alkaliThis question was posed to me in final exam.This interesting question is from Classification of Lubricants topic in portion Lubricants of Applied Chemistry

To improve the refined petroleum oils ___________ are added.(a) Additives(b) Inhibitors(c) Catalysts(d) CarbonThis question was posed to me during a job interview.My question is based upon Classification of Lubricants in section Lubricants of Applied Chemistry

What is the range of coefficient of friction for solid lubricants?(a) 0.005-0.01(b) 0.001-0.01(c) 0.0001-0.001(d) 0.0005-0.001This question was addressed to me during an interview for a job.The query is from Classification of Lubricants in chapter Lubricants of Applied Chemistry