Tribology Exam 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Kinematic and absolute (dynamic) viscosity are related via - CORRECT ANSWER -
density
The viscosity of lubricants may ______ with increasing pressure - CORRECT ANSWER -
increase
The viscosity of lubricants may ______ with increasing temperature - CORRECT
ANSWER - decrease
The viscosity of lubricants may ______ with increasing shear rate - CORRECT
ANSWER - decrease
The rate of change of viscosity with temperature is - CORRECT ANSWER - faster than
linear
Elongation of molecular chains in the direction of shear leads to ______ viscosity loss -
CORRECT ANSWER - temporary
Scission of molecular chains leads to ______ viscosity loss - CORRECT ANSWER -
permanent
The critical shear rate determines the onset of shear thinning. For a lubricant, it is desirable for
the critical shear rate to be - CORRECT ANSWER - high
Instruments for measuring viscosity are called - CORRECT ANSWER - rheometers
, If the density of an oil is 0.8 g/cm² at 15.6°C, the specific gravity of that oil is - CORRECT
ANSWER - 0.8
Degrees API is another measure of - CORRECT ANSWER - density
The rate of decrease of density with increasing temperature is ______ the rate of decrease of
viscosity with increasing temperature - CORRECT ANSWER - slower than
The rate of decrease of viscosity with increasing temperature is ______ the rate of decrease of
density with increasing temperature - CORRECT ANSWER - slower than
Thermal conductivity and specific heat of a lubrication are important because they directly
determine the - CORRECT ANSWER - rate of frictional heat dissipation
______ makes up most of a lubricating oil or grease - CORRECT ANSWER - base oil
______ contains thickener - CORRECT ANSWER - grease
The process of distilling mineral oil from crude oil is based on the fact that higher molecular
weight species condense (change from gas to liquid) at ______ temperature - CORRECT
ANSWER - lower
______ base oils are likely to be the least expensive - CORRECT ANSWER - mineral
______ base oils are expected to be the most susceptible to oxidation - CORRECT
ANSWER - mineral
______ base oils would be used if you wanted to mix it with a mineral base oil - CORRECT
ANSWER - synthetic hydrocarbon
Exam Questions and CORRECT Answers
Kinematic and absolute (dynamic) viscosity are related via - CORRECT ANSWER -
density
The viscosity of lubricants may ______ with increasing pressure - CORRECT ANSWER -
increase
The viscosity of lubricants may ______ with increasing temperature - CORRECT
ANSWER - decrease
The viscosity of lubricants may ______ with increasing shear rate - CORRECT
ANSWER - decrease
The rate of change of viscosity with temperature is - CORRECT ANSWER - faster than
linear
Elongation of molecular chains in the direction of shear leads to ______ viscosity loss -
CORRECT ANSWER - temporary
Scission of molecular chains leads to ______ viscosity loss - CORRECT ANSWER -
permanent
The critical shear rate determines the onset of shear thinning. For a lubricant, it is desirable for
the critical shear rate to be - CORRECT ANSWER - high
Instruments for measuring viscosity are called - CORRECT ANSWER - rheometers
, If the density of an oil is 0.8 g/cm² at 15.6°C, the specific gravity of that oil is - CORRECT
ANSWER - 0.8
Degrees API is another measure of - CORRECT ANSWER - density
The rate of decrease of density with increasing temperature is ______ the rate of decrease of
viscosity with increasing temperature - CORRECT ANSWER - slower than
The rate of decrease of viscosity with increasing temperature is ______ the rate of decrease of
density with increasing temperature - CORRECT ANSWER - slower than
Thermal conductivity and specific heat of a lubrication are important because they directly
determine the - CORRECT ANSWER - rate of frictional heat dissipation
______ makes up most of a lubricating oil or grease - CORRECT ANSWER - base oil
______ contains thickener - CORRECT ANSWER - grease
The process of distilling mineral oil from crude oil is based on the fact that higher molecular
weight species condense (change from gas to liquid) at ______ temperature - CORRECT
ANSWER - lower
______ base oils are likely to be the least expensive - CORRECT ANSWER - mineral
______ base oils are expected to be the most susceptible to oxidation - CORRECT
ANSWER - mineral
______ base oils would be used if you wanted to mix it with a mineral base oil - CORRECT
ANSWER - synthetic hydrocarbon
