Download 45 Questions and Answers on Power Engineering Class 4B Book 1: Lubrication and Bearings and more Exams Engineering in PDF only on Docsity!
45 Questions and Answers on
Power Engineering Class 4B Book 1
Lubrication and Bearings
d - โ โ Large journal or sleeve bearings have grooves
a) In the high pressure area of the bearing babbit b) Cut into the bearing housing c) For distributing lubricant evenly just after the pressure area d) In the non-pressure area
c - โ โ Using pressurized air to blow out a cleaned bearing
a) Should only be done in well ventilated areas b) Must be done only when the bearing is hot c) Will cause the bearing to become pitted d) Should be done at an angle so the bearing can spin
d - โ โ A collar type bearing a) Can support more load than the mitchell thrust bearing b) Is an anti friction type bearing c) is used with steam turbines only d) Has boundary lubrication
d - โ โ a common cause of anti friction failure is
a) high RPM service b) extreme cold temperature cracking c) drive motor overload d) shaft misalignment
d - โ โ A journal bearing
a) controls thrust movement b) does not require lubrication c) require cooling water d) supports a shaft
b) Forced lubrication c) Continuous lubrication d) Boundary lubrication
c - โ โ With anti friction bearings using grease, the bearings
a) must be cleaned twice as often as oil-lubricated bearings b) can be cleaned by adding solvent to the grease cartridge c) are cleaned less often the oil-lubricated bearings d) never require cleaning
c - โ โ the majority of lubricants are
a) Animal fats b) Synthetic oils c) Mineral oils d) Greases
c - โ โ the point at which oil will give off enough vapour the ignite and burn continuously is known as the ____________ point
a) flash b) ignition c) fire d) vaporization
d - โ โ A Shell type Bearing
a) Is used for axial thrust b) is an anti friction bearing c) Consists of ball bearings in a shell d) Is used for heavy loads
d - โ โ Grease
a) Is a semi-liquid b) is an excellent high-speed, low load lubriction
a) Have a low pour point b) Have a high flashpoint c) Have a high fire point d) Be multi-grade type
a - โ โ The property of oil that indicates its ability to support a load is
a) Viscosity b) Viscosity Index c) Pour point d) Floc point
a - โ โ When grease is used in a anti friction bearing after cleaning, the bearing housing should not be filled _________ full
a) more than 1/ b) more than 1/
c) more than 3/ d) less than completely
a - โ โ When replacing or removing an anti-friction bearing , the applied force should
a) Not be transmitted through the balls b) Always be against the inner race c) Always be against the outer race d) Be made only after heating the bearing
a - โ โ Which type of oil produces higher fluid friction
a) High viscosity oil b) Low viscosity oil c) Synthetic oil d) Fixed oil
b - โ โ A large journal bearing which is running hotter than normal can be cooled by
b - โ โ If an oil must flow at a very low temperature, it must have the following additives
a) Viscosity index improver b) Pour point depressant c) Dispersant d) Floc point improver
b - โ โ Lubricants used for high-output steam turbines should
a) Have a very high viscosity b) Be fire resistant c) Have a low pour point d) Mix well with water
b - โ โ The ability of an oil to lift and support heavy loads depends on
a) Kinetic energy
b) Hydraulic pressure c) Acceleration d) Pour point
b - โ โ The instrument that measures the viscosity of an oil at a certain temperature as it flows through a small diameter tube is called
a) an orfice plate b) a staybolt viscometer c) an oil meter d) a vena contracta
b - โ โ The kind of grease used for heavy loads at slow speeds is the
a) Sodium base grease b) Specialty grease c) Calcium base grease d) Aluminum base grease
b) 10 mm c) 1.25 cm d) 1.7 cm
c - โ โ A material that is commonly used as a solid lubricant is
a) Tallow b) Lime c) Molybdenum Disulphide d) Sodium Carbonate
c - โ โ A normal anti-friction bearing temperature operating temperature is
a) 150c - 160c b) 20c - 50c c) 65c - 70c d) 80c - 120c
c - โ โ An anti friction bearing
a) is constructed with white metal alloy b) wears to a smooth, low friction surface c) has rolling friction d) is a sleeve bearing
c - โ โ Fluid-film lubrication
a) eliminates all bearing friction b) is different from flood lubrication c) Supports heavy loads d) Prevents wear during start-up
c - โ โ The _____________ number indicates the acidity of oil
a) Acidity b) Alkalinity c) Neutralization d) Viscosity Index
d) Not contain anti-oxidants
c - โ โ The cheapest and most commonly used grease is
a) Potassium base b) Chlorine base c) Lime base d) Sulphate base
c - โ โ The lubricant for an anti friction bearing
a) will separate the moving parts completely b) must be cooled c) Could be a semi-solid lubricant d) should have a high viscosity
c - โ โ where gears intermesh, a lubricant must provide
a) corrosion prevention b) sealing c) shock absorption
d) Temperature control
c - โ โ Which of the following has the greatest effect on the viscosity of a lubrication oil
a) Pressure b) Load c) Temperature d) Speed
d - โ โ Grease is not a suitable lubricant
a) If the atmosphere contains a lot of moisture b) When the atmosphere is dusty c) If corrosion protection is desired during downtime d) If a large amount of cooling is desired
d - โ โ If an oils viscosity changes a lot with very little temperature change, it will have a
a) Low pour point
