Viscosity index improver (like polystyrene or polyisobutylene) is added to lubricant to (A) Reduce its viscosity (B) Increase its viscosity (C) Reduce the variation in its viscosity with temperature(D) Increase the variation in its viscosity with temperature

Viscosity index improver (like polystyrene or polyisobutylene) is added
to lubricant to
(A) Reduce its viscosity
(B) Increase its viscosity
(C) Reduce the variation in its viscosity with temperature
(D) Increase the variation in its viscosity with temperature
by

1 Answer

Answer :

(C) Reduce the variation in its viscosity with temperature
by

Related questions

In cold countries ethylene glycol is added to water in car radiators. This helps to (a) Reduce the viscosity (b) Make water a better lubricant (c) Lower the freezing point (d) Lower the boiling poin

Description : In cold countries ethylene glycol is added to water in car radiators. This helps to (a) Reduce the viscosity (b) Make water a better lubricant (c) Lower the freezing point (d) Lower the boiling poin

Last Answer : Lower the freezing point

A good lubricant should have high (A) Viscosity index (B) Volatility (C) Pour point (D) None of these

Description : A good lubricant should have high (A) Viscosity index (B) Volatility (C) Pour point (D) None of these

Last Answer : (A) Viscosity index

Viscosity index of a lubricating oil (A) Is the measure of its flash point (B) Is the measure of variation of viscosity with temperature (C) Should be low (D) None of these

Description : Viscosity index of a lubricating oil (A) Is the measure of its flash point (B) Is the measure of variation of viscosity with temperature (C) Should be low (D) None of these

Last Answer : (B) Is the measure of variation of viscosity with temperature

Define cloud point and viscosity index of a lubricant

Description : Define cloud point and viscosity index of a lubricant

Last Answer : Cloud point: Cloud point indicates the temperature at which the oil becomes cloudy in appearance, due to separation of wax. Viscosity Index: The rate of change of viscosity of a liquid (Oil) with the change of temperature is known as viscosity index.

Peptizers like aromatic mercaptans (e.g. thiophenes) are added in rubber to (A) Protect rubber goods from attack by oxygen & ozone present in the atmosphere (B) Reduce its viscosity to permit easier processing (C) Reduce the time of vulcanisation and quantity of vulcanising agent (D) Increase its viscosity

Description : Peptizers like aromatic mercaptans (e.g. thiophenes) are added in rubber to (A) Protect rubber goods from attack by oxygen & ozone present in the atmosphere (B) Reduce its viscosity to ... processing (C) Reduce the time of vulcanisation and quantity of vulcanising agent (D) Increase its viscosity

Last Answer : (B) Reduce its viscosity to permit easier processing

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Last Answer : (B) Act as an antioxidant

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Last Answer : (B) Variation in cost in materials element, labour element and petrol-oil-lubricant element

In a journal bearings, the radius of the friction circle increases with the increase in- [IES-1997] (a) Load (b) Radius of the journal (c) Speed of the journal (d) Viscosity of the lubricant

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Last Answer : (b) Radius of the journal

A lubricant 100 times more viscous than water would have a viscosity (in Pa.s) (A) 0.01 (B) 0.1 (C) 1 (D) 10

Description : A lubricant 100 times more viscous than water would have a viscosity (in Pa.s) (A) 0.01 (B) 0.1 (C) 1 (D) 10

Last Answer : (B) 0.1

Limestone is added in the blast furnace (during pig iron manufacture) to (A) Form slag by combining with impurities (B) Supply heat by undergoing exothermic reaction with impurities (C) Reduce the coke consumption (D) Reduce slag viscosity

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Last Answer : Option A

Phosphates (e.g., tricresyl, tributyl, tetrabutyl, triphenyl etc.) are addedto polymers to act as(A) Hardeners(B) Anti-shrinkage agents(C) Plasticisers(D) Transparency improver

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Last Answer : (C) Plasticisers

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Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments (B) Pressure drop in the equipment will be very high (C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments

Satisfactory hydrodynamic film in a journal bearing is formed when (a) Journal speed is low; unit pressure on the bearing is high and viscosity of lubricant used is low [IES-2006] (b) Journal speed is low; unit pressure on the bearing is low and viscosity of lubricant used is low (c) Journal speed is high; unit pressure on the bearing is high and viscosity of lubricant used is high (d) Appropriate combination of journal speed, unit pressure on bearing and lubricant viscosity exists resulting in low coefficient of friction

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Consider the following statements: [IES 2007] For a journal rotating in a bearing under film lubrication conditions, the frictional resistance is- 1. Proportional to the area of contact 2. Proportional to the viscosity of lubricant 3. Proportional to the speed of rotation 4. Independent of the pressure Which of the statements given above are correct? (a) 1, 2, 3 and 4 (b) 1 and 4 only (c) 2, 3 and 4 only (d) 2 and 3 only

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Last Answer : (a) 1, 2, 3 and 4

In MS Word, which checks active document for spelling and grammatical errors is: a) Spell Corrector b) Spell Checker c) Spell Improver d) None of These

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Last Answer : b) Spell Checker

Higher viscosity index of a lubricating oil denotes (A) Less changes in fluidity of oil with temperature (B) Substantially high change in fluidity of oil with temperature (C) Its unsuitability under varying temperature conditions (D) None of these

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Last Answer : (A) Less changes in fluidity of oil with temperature

The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same. (A) Kinematic viscosity (B) Work (C) Temperature (D) None of these

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________ is a substance that can reduce the force of friction between the two surface in contact. a) lubricant b)paste c)water d)push

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. Pick out the wrong statement. (A) Multigrade lubricating oils have high viscosity index (B) Paraffinic oil has very high viscosity index (C) Naphthenic oil has very low viscosity index (D) High viscosity index means a large change in viscosity with change in temperature

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Presence of predominantly large quantity of aromatics (polynuclear) is not desirable in aviation fuel, because it has (A) High pour point and low smoke point (B) Low viscosity index (C) High self-ignition temperature (D) All (A), (B) and (C)

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Last Answer : (B) Low viscosity index

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Last Answer : (D) An oil having high susceptibility to change in viscosity with temperature changes, has a high viscosity index

Addition of stabiliser during PVC manufacture is done to (A) Improve its impact strength (B) Improve its elasticity (C) Reduce the melt viscosity & glass transition temperature (D) Prevent its thermal degradation

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Last Answer : (D) Prevent its thermal degradation

45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

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Mercaptans are added to liquefied petroleum gas (LPG) to (A) Reduce its cost (B) Narrow down its explosion limit (C) Assist in checking its leakage from cylinder (D) Increase its calorific value

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Last Answer : (C) Assist in checking its leakage from cylinder

Tetra-ethyl lead is added in gasoline to (A) Increase its smoke point (B) Reduce gum formation(C) Reduce the pour point(D) Increase its octane numbe

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Last Answer : (D) Increase its octane numbe

The variation in the volume of a liquid with the variation of pressure is called its (A) Surface tension (B) Compressibility (C) Capillarity (D) Viscosity

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Upto the critical radius of insulation, added insulation, will (A) Increase the heat loss (B) Decrease heat loss and will have no effect beyond that (C) Decrease heat flux (D) Reduce convection heat loss compared to conduction heat less

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Last Answer : Option B

Mineral oils (e.g. petroleum oils) are preferred over fatty oils (e.g. mustard oil, ghee, tallow, palm oil, olive oil etc.) as a lubricant due to its (A) Poor oxidation stability and high gum forming tendency (B) Greater tendency of decomposition at elevated temperature (C) Hydrolysis tendency in presence of water (D) All (A), (B) and (C)

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Last Answer : (D) All (A), (B) and (C)

Thermocol (expanded polystyrene) is not used for (A) Low temperature thermal insulation as in refrigerator and air conditioners (B) Acoustic control and ceiling for building (C) High temperature thermal insulation in furnaces (D) Packing of delicate electronic gadgets

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Last Answer : (A) As room temperature adhesive

The best lubricants for a machine working at high temperature & load is (A) Grease (B) Solid lubricant (C) Animal oils (D) Mineral oils

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Small amount of gasoline is added to alcohol to a) reduce the emission b) to increase the power output c) to increase the efficiency d) to improve cold weather starting

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Last Answer : (B) Reduce the maximum quantization error.

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In extractive distillation, solvent is (A) Added to alter the relative volatility of the mixture (B) Of high volatility (C) Present in overhead stream (D) Of high viscosity to give high tray efficiency

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Last Answer : (A) Added to alter the relative volatility of the mixture

Which one is preferred for aircraft engine? (A) High viscosity index lube oil (B) Low viscosity index lube oil (C) High freezing point aviation fuel (D) None of these

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Last Answer : (A) High viscosity index lube oil

Hydrofining is the most recent and effective method for the (A) Removal of sulphur (B) Improvement of smoke point (C) Reduction of breathing loss (D) Improvement of viscosity index

Description : Hydrofining is the most recent and effective method for the (A) Removal of sulphur (B) Improvement of smoke point (C) Reduction of breathing loss (D) Improvement of viscosity index

Last Answer : (A) Removal of sulphur

Paraffin base crude oil as compared to asphalt base crude gives (A) Higher yield of straight run gasoline (B) Higher octane number gasoline (C) Lower viscosity index lube oil (D) Poorer yield of lube oil

Description : Paraffin base crude oil as compared to asphalt base crude gives (A) Higher yield of straight run gasoline (B) Higher octane number gasoline (C) Lower viscosity index lube oil (D) Poorer yield of lube oil

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A multigrade lubricating oil means an oil having high (A) Viscosity index (B) Viscosity (C) Aniline point (D) Flash point

Description : A multigrade lubricating oil means an oil having high (A) Viscosity index (B) Viscosity (C) Aniline point (D) Flash point

Last Answer : (A) Viscosity index

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Paraffins are desirable in lubricating oil, as it has got high (A) Viscosity (B) Viscosity index (C) Smoke point (D) Pour poin

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The intensive properties are (A) Molar volume, density, viscosity and boiling point (B) Refractive index and surface tension (C) Both (A) and (B) (D) None of these

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