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25 Cards in this Set
- Front
- Back
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1) A machine is a device for converting force to useful work. It cannot be used to ---
(A) change the size of the force (B) change the direction of a force (C) change the speed or rate a force is acting (D) multiply the force factor without reducing the distance factor |
(D) multiply the force factor without reducing the distance factor
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2) Of the below statements concerning machine efficiency, which one is not a true statement?
(A) input is equal to useful output plus useless output (B) efficiency is equal to useful output divided by input (C) transformers are less efficient than reciprocating pumps (D) improper operation of the machine can seriously affect the efficiency |
C) transformers are less efficient than reciprocating pumps
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3) The friction created by a shaft or journal revolving in an oil-lubricated bearing is called ---
(A) sliding friction (B) rolling friction (C) fluid friction (D) a combination of all three |
(C) fluid friction
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4) A bearing which restricts or supports the longitudinal motion of a rotating shaft is called a ---
(A) thrust bearing (B) radial bearing (C) journal bearing (D) guide bearing |
(A) thrust bearing
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5) All of the below factors influence the design of plain bearings for large generator applications. Which of these factors is more directly controlled by the operator in order to obtain and maintain the oil wedge desired for proper lubrication?
(A) bearing clearance (B) viscosity of the lubricant (C) shaft or journal speed (D) bearing load |
(B) viscosity of the lubricant
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6) The location of the pressure area in a bearing ---
(A) changes with changes in journal speed (B) never changes (C) is normally closer to the top than to the bottom of the bearing (D) is not a factor in the formation of the desired oil wedge |
(A) changes with changes in journal speed
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7) A prerequisite to the formation of a strong oil wedge is -
(A) comparatively large bearing clearance and light oil (B) comparatively small bearing clearance and light oil (C) comparatively small bearing clearance and heavy oil (D) to keep the bearing lightly loaded |
(B) comparatively small bearing clearance and light oil
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8) While bearing clearances will vary somewhat because of different design, bearing material, and loading characteristics, it is generally established that for each inch of shaft diameter the clearance should be about ---
(A) 0.001" (B) 0.002" (C) 0.003" (D) 0.004" |
(A) 0.001"
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9) Heavily loaded bearings ---
(A) require slower journal speeds (B) are less likely to fail at higher journal speeds (C) will form an oil wedge in less time than lightly loaded bearings (D) are more likely to fail during a momentary loss of the oil film than lightly loaded bearings |
(D) are more likely to fail during a momentary loss of the oil film than lightly loaded bearings
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10) All of the below statements concerning oil grooves in bearings are true except for ---
(A) the oil groove is generally located in the high-pressure area of the bearing (B) an oil groove delivers oil over the bearing surfaces just ahead of the high-pressure area (C) oil grooves help to prevent the loss of oil through the side of the bearing (D) oil grooves should stop at least 1/2 inch from each end of the bearing |
(A) the oil groove is generally located in the high-pressure area of the bearing
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11) The proper way to install a ball or roller bearing is to -
(A) use a firm press fit for both the outer and inner race (B) use a loose running fit for both the outer and inner race (C) install the outer race in the machine housing using a frim press fit (D) install the inner race on the shaft or journal using a firm press fit |
(D) install the inner race on the shaft or journal using a firm press fit
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12) The kind of load an anti-friction bearing will carry is generally determined by the ---
(A) shape of the rollers (B) shape of the bearing races (C) size of the shaft (D) size of the bearing |
(B) shape of the bearing races
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13) Which of the following would be less likely to affect the bearing life of an anti-friction bearing?
(A) over lubrication (B) improper installation (C) pitting of ball and raceways (D) load and speed |
(D) load and speed
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14) If the oil reservoir in a ring-oiled bearing is carried too high, the oil ring ---
(A) will stop turning (B) will turn faster (C) will turn more slowly (D) will cause the bearing to flood |
(C) will turn more slowly
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15) The desired oil wedge is formed in a Kingsbury thrust bearing by ---
(A) pumping action (B) action of the pivoted shoes or blocks (C) pressurized lubrication (D) using a heavy oil |
(B) action of the pivoted shoes or blocks
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16) Which of the following statements concerning tapered-land thrust bearings is true?
(A) the bearing uses two rotating thrust collars (B) the bearing runs in a tub of oil (C) ther bearing lands are supported on rounded pivots (D) the babbited surfaces of the bearing do not require oil grooves |
(A) the bearing uses two rotating thrust collars
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17) All of the below statements regarding the Kingsbury pivoted-shoe type thrust bearing are true except for ---
(A) the stationary faces may be divided into four, six or eight pie-shaped segments (B) the shoes are supported at the center of gravity on a rounded pivot (C) the oil wedge is not affected by load conditions (D) the thrust collar is smoothly ground steel |
(C) the oil wedge is not affected by load conditions
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18) Anti-friction bearings ---
(A) are not designed to accept angular loading (B) are routinely replaced after 1000 hours of operation (C) should always be replaced upon finding evidence of pitting and flaking (D) are satisfactory for reuse if there is no evidence of corrosion and only a slight amount of pitting an flaking |
(C) should always be replaced upon finding evidence of pitting and flaking
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19) Which of the below features does not apply to radial type bearings?
(A) depends on pumping action between the journal and bearings to establish oil film (B) may be split or one piece (C) both bearing and journal may rotate (D) they may be designed to carry a load parallel to the shaft axis |
(D) they may be designed to carry a load parallel to the shaft axis
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20) Bearing corrosion may be caused by ---
(A) improper operating characteristics (B) improperly formed oil wedge (C) improper bearing clearance (D) using improper type of lube oil |
(D) using improper type of lube oil
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21) The overall length of the below crankshaft is ---
(Drawing to be added later) (A) less than 30 inches (B) between 30 and 31 inches (C) greater than 31 but less than 32 inches (D) greater than 32 inches |
(D) greater than 32 inches
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22) Determine the overall length of the below crankshaft in decimal form (three places) (Drawing to be added later)
(A) 9.453 (B) 10.353 (C) 10.453 (D) none of these |
(C) 10.453
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23) Determine the square root of 2937.64 --
(A) 51.8 (B) 54.2 (C) 55.2 (D) 58.8 |
(B) 54.2
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24) Determine the perimeter of a square when the area is 81 square inches ---
(A) 26 inches (B) 27 inches (C) 36 inches (D) none of these |
(C) 36 inches
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25) Determine the weight which can be moved up an incline 12 feet long and 4 feet high by a force of 100 lb when power is applied parallel to the incline
(disregard friction and formula is P X L = W X H) (A) 300 lb (B) 325 lb (C) 350 lb (D) none of these |
(A) 300 lb
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