Power Engineer Class 4 Part B All Questions With Complete Solutions
Most important purposes of lubrication are: - (ANSWER)Friction reduction, wear reduction and
corrosion reduction
The separation of contacting surfaces is achieved by: - (ANSWER)Lubrication
Friction can be described as : - (ANSWER)a resistance to motion
lubrication principle purposes: - (ANSWER)reduce friction
reduce wear
corrosion reduction
control the Temp
shock absorber
provide sealing
* major purpose reduce friction and wear.
Semi solid lubricants pr greases are made by combining a liquid lubricant usually: - (ANSWER)petroleum
oil with a thickening agent.
The fact that grease has a thick, stiff consistency means that it can be used under conditions where oil
could leak or drain away, leaving the bearing dry. Also grease is less likely to drip or splash from
bearings. Therefore, it has a wide application in the: - (ANSWER)Textile and food industires
Grease is suitable for: - (ANSWER)Ball bearings and roller bearings
Grease is not suitable where large amounts of: - (ANSWER)Heat must be continually carried away from
the bearing. under these conditions, a liquid lubricant would be used.
Specialty greases are mad of: - (ANSWER)Mineral oils thickened with soil lubricants such as graphite,
mica, and talc. They are used for heavily operated machinery that operate at slow speeds.
,Power Engineer Class 4 Part B All Questions With Complete Solutions
Liquid lubricants are divided into 3 general classes: - (ANSWER)1 mineral oils
2. fixed oils
3. synthetic oils
Mineral oils are produced from: - (ANSWER)crude petroleum
Mineral oils are the most: - (ANSWER)commonly used class of lubricants.
Cooling for oil lubricated, heavily loaded bearings can be: - (ANSWER)A separate oil cooler
Lubricants act as a: - (ANSWER)cushion to absorb shock( gear teeth)
Mineral oils constitute the majority of all: - (ANSWER)lubricants from crude petroleum
Greases are a : - (ANSWER)Mixture of mineral oil and thickening agents.
Viscosity is a measure of the resistance of a : - (ANSWER)Liquid to internal deformation or shear. it
indicates the liquids ability to flow.
Viscosity indicates the: - (ANSWER)-ability of an oil to a support a load
- Power required to overcome internal friction
- amount of heat produced due to internal friction
Oil viscosity is greatly affected by: - (ANSWER)Its temperature
as temperature increases in viscosity oil will become: - (ANSWER)thinner and less viscous (viscosity will
be reduced)
,Power Engineer Class 4 Part B All Questions With Complete Solutions
as temperature decreases in oil viscosity will be - (ANSWER)Thicker and more viscous (viscosity will be
increased)
A commonly used method to measure viscosity of oil is: - (ANSWER)Saybolt viscometer
in a saybolt viscometer, the units are expressed in: - (ANSWER)Saybolt Seconds Universal (SSU)
the viscosity index is a: - (ANSWER)Measuremnt of how much the viscosity of a certain oil changes with
a temperature change.
The pour point of oil is the: - (ANSWER)Lowest tempt which a certain oil will flow.
Oils used in cold climates must have a - (ANSWER)Low pour point
The flash point of a oil is the - (ANSWER)temp at which it will give off sufficient vapour to ignite
the fire point of an oil is - (ANSWER)the temp at which it gives off enough vapour to burn continuously
Some lubricating oil additives are: - (ANSWER)-anti oxidants
-detergent- dispersants
-viscostiy index improvers
-antifoam additives
-pour point depressants
- corrosion inhibitors
Lubrication can be generally divided into 2 categories: - (ANSWER)1. boundary lubrication
2. FLuid film lubrication
boundary lubrication: - (ANSWER)only a microscopic film of lubricant separates the surfaces.
, Power Engineer Class 4 Part B All Questions With Complete Solutions
Fluid film lubrication - (ANSWER)Is also called flood lubrication
Friction between 2 surfaces can be defined quite simply as: - (ANSWER)resistance to motion (or
attempted motion)
The purpose of lubricants is to - (ANSWER)reduce the friction and wear
other then friction and wear lubricants control: - (ANSWER)Corrosion, absorb shock, seal and provide
temp control
Causes of sleeve bearing failure: - (ANSWER)-improper viscosity of oil
-improper bearing design (oil groove, chamfer, clearance)
-misalignment of shaft and bearing
-loss of bearing metal due to corrosion or metal fatigue
-loss of oil supply
-temp of oil to high
extreme bearing temps could lead to trouble. to prevent this from happening these bearings are usually
: - (ANSWER)water cooled
a non water cooled bearing may be cooled by directing a flow of cooling air to the bearing, via electric
fan or: - (ANSWER)eductor horn
if cooling is required grease is : - (ANSWER)not suitable
the ability of an oil to support its load is the - (ANSWER)viscosity
a high viscosity index number means the viscosity will: - (ANSWER)change little with temp change
Most important purposes of lubrication are: - (ANSWER)Friction reduction, wear reduction and
corrosion reduction
The separation of contacting surfaces is achieved by: - (ANSWER)Lubrication
Friction can be described as : - (ANSWER)a resistance to motion
lubrication principle purposes: - (ANSWER)reduce friction
reduce wear
corrosion reduction
control the Temp
shock absorber
provide sealing
* major purpose reduce friction and wear.
Semi solid lubricants pr greases are made by combining a liquid lubricant usually: - (ANSWER)petroleum
oil with a thickening agent.
The fact that grease has a thick, stiff consistency means that it can be used under conditions where oil
could leak or drain away, leaving the bearing dry. Also grease is less likely to drip or splash from
bearings. Therefore, it has a wide application in the: - (ANSWER)Textile and food industires
Grease is suitable for: - (ANSWER)Ball bearings and roller bearings
Grease is not suitable where large amounts of: - (ANSWER)Heat must be continually carried away from
the bearing. under these conditions, a liquid lubricant would be used.
Specialty greases are mad of: - (ANSWER)Mineral oils thickened with soil lubricants such as graphite,
mica, and talc. They are used for heavily operated machinery that operate at slow speeds.
,Power Engineer Class 4 Part B All Questions With Complete Solutions
Liquid lubricants are divided into 3 general classes: - (ANSWER)1 mineral oils
2. fixed oils
3. synthetic oils
Mineral oils are produced from: - (ANSWER)crude petroleum
Mineral oils are the most: - (ANSWER)commonly used class of lubricants.
Cooling for oil lubricated, heavily loaded bearings can be: - (ANSWER)A separate oil cooler
Lubricants act as a: - (ANSWER)cushion to absorb shock( gear teeth)
Mineral oils constitute the majority of all: - (ANSWER)lubricants from crude petroleum
Greases are a : - (ANSWER)Mixture of mineral oil and thickening agents.
Viscosity is a measure of the resistance of a : - (ANSWER)Liquid to internal deformation or shear. it
indicates the liquids ability to flow.
Viscosity indicates the: - (ANSWER)-ability of an oil to a support a load
- Power required to overcome internal friction
- amount of heat produced due to internal friction
Oil viscosity is greatly affected by: - (ANSWER)Its temperature
as temperature increases in viscosity oil will become: - (ANSWER)thinner and less viscous (viscosity will
be reduced)
,Power Engineer Class 4 Part B All Questions With Complete Solutions
as temperature decreases in oil viscosity will be - (ANSWER)Thicker and more viscous (viscosity will be
increased)
A commonly used method to measure viscosity of oil is: - (ANSWER)Saybolt viscometer
in a saybolt viscometer, the units are expressed in: - (ANSWER)Saybolt Seconds Universal (SSU)
the viscosity index is a: - (ANSWER)Measuremnt of how much the viscosity of a certain oil changes with
a temperature change.
The pour point of oil is the: - (ANSWER)Lowest tempt which a certain oil will flow.
Oils used in cold climates must have a - (ANSWER)Low pour point
The flash point of a oil is the - (ANSWER)temp at which it will give off sufficient vapour to ignite
the fire point of an oil is - (ANSWER)the temp at which it gives off enough vapour to burn continuously
Some lubricating oil additives are: - (ANSWER)-anti oxidants
-detergent- dispersants
-viscostiy index improvers
-antifoam additives
-pour point depressants
- corrosion inhibitors
Lubrication can be generally divided into 2 categories: - (ANSWER)1. boundary lubrication
2. FLuid film lubrication
boundary lubrication: - (ANSWER)only a microscopic film of lubricant separates the surfaces.
, Power Engineer Class 4 Part B All Questions With Complete Solutions
Fluid film lubrication - (ANSWER)Is also called flood lubrication
Friction between 2 surfaces can be defined quite simply as: - (ANSWER)resistance to motion (or
attempted motion)
The purpose of lubricants is to - (ANSWER)reduce the friction and wear
other then friction and wear lubricants control: - (ANSWER)Corrosion, absorb shock, seal and provide
temp control
Causes of sleeve bearing failure: - (ANSWER)-improper viscosity of oil
-improper bearing design (oil groove, chamfer, clearance)
-misalignment of shaft and bearing
-loss of bearing metal due to corrosion or metal fatigue
-loss of oil supply
-temp of oil to high
extreme bearing temps could lead to trouble. to prevent this from happening these bearings are usually
: - (ANSWER)water cooled
a non water cooled bearing may be cooled by directing a flow of cooling air to the bearing, via electric
fan or: - (ANSWER)eductor horn
if cooling is required grease is : - (ANSWER)not suitable
the ability of an oil to support its load is the - (ANSWER)viscosity
a high viscosity index number means the viscosity will: - (ANSWER)change little with temp change
