1) Which gear is used if the axes of two shafts are neither intersecting nor parallel?
a. Hypoid gears
b. Worm gears
c. Both a and b
d. None of the above
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2) Spiral gears are used only if the axes of two shafts are non-intersecting, non-parallel and __________.
a. perpendicular
b. parallel
c. non-perpendicular
d. none of the above
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3) In which of the following processes, tooth ends are made thinner?
a. Backlash effect
b. Crowing of gear tooth
c. Hunting of gear tooth
d. None of the above
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4) What are the advantages of smaller pressure angles?
a. High radial force
b. High separating force
c. High contact ratio
d. All of the above
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5) In force analysis of spur gears which component of force assists the rotation on driven gear?
a. Axial component
b. Radial component
c. Tangential component
d. All of the above
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6) A helical gear has normal module of 6 mm. What is the transverse module if helix angle is 25o?
a. 4.95 mm
b. 500 mm
c. 5.43 mm
d. 6.62 mm
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7) What is the axial pitch for helical gears if helix angle is 25o and normal module is 7?
a. 50.55 mm
b. 52.03 mm
c. 32.15 mm
d. 11.31 mm
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8) A helical gear made of plain carbon steel has face width 10 times the normal module. If number of teeth on pinion and gear are 20 and 60 respectively, then what will be the wear strength of helical gear? (Assume mn = 5, BHN = 200 & Ψ = 24o)
a. 5751.30 N
b. 5230.19 N
c. 6295.58 N
d. 6891.37 N
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9) Which of the following formulae of velocity factor (K) is considered if helical gears of medium accuracy are manufactured by hobbing process followed by shaving?
a. 5.6 / (5.6 + √V)
b. √5.6 / (5.6+ √V)
c. 6 / (6+V)
d. 0.85
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10) A helical gear transmits power of 2050 W and has helix angle of 25o. If pitch line velocity is 15 m/s then what is the maximum tangential force acting on helical gear tooth? (Assume Ka = 1 & Km = 1.2)
a. 113.88 N
b. 136 N
c. 164 N
d. None of the above
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11) What is the pitch cone distance of bevel gear, if pitch circle diameter of bevel pinion and gear is 20 and 30 respectively?
a. 100 mm
b. 18.02 mm
c. 21.32 mm
d. 25 mm
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12) A pair of straight bevel gears consists of 16 pinion teeth and 42 gear teeth. What are the pitch cone angles of pinion and gear?
67.60o & 32.4o?
a. 67.60o & 22.39o
b. 52.14o & 37.86o
c. 20.85o & 69.14o
d. 35.12o & 54.88o
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13) Virtual number of teeth on pinion of bevel gear is calculated using the formula __________
(where zp = number of teeth on pinion, γp & γg = pitch cone angle)
a. zp / cos γp
b. zp / cos γg
c. zp / cos2 γp
d. zp / cos3 γp
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14) What is the axial force acting on the pinion if a bevel gear transmits power of 20 kW with a mean pitch line velocity of 5 m/s?
(Consider γp = 25o & Φ = 15o)
a. 1865 N
b. 1801.67 N
c. 971.37 N
d. 452.96 N
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15) A straight bevel gear pinion rotates at 800 r.p.m transmitting power of 15 kW to the bevel gear. If pitch circle diameter of pinion is 130 mm and face width is 30 mm, then what is the tangential force acting on mean pitch circle?
( γp = 23o & γg = 53o)
a. 3461.53 N
b. 2988.12 N
c. 3027.30 N
d. Insufficient data
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16) What is the frictional torque acting on a cylindrical roller bearing of 50 mm diameter which is subjected to radial load of 30 kN and has coefficient of friction 0.0011?
a. 109 kN-mm
b. 900 kN-mm
c. 825 N-mm
d. 1650 N-mm
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17) A cylindrical roller bearing is subjected to frictional torque of 500 N-mm. What is the approximate power loss if the shaft rotates at 1500 r.p.m?
a. 0.0785 kW
b. 0.0392 kW
c. 0.0526 W
d. 0.0236 W
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18) What will be the static capacity of single-row deep groove ball bearing having 10 balls of 15 mm?
(Assume K = 62 N/mm2)
a. 25900 kN
b. 124 kN
c. 31.00 kN
d. 27.900 kN
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19) Which of the following is a Stribeck's equation to determine basic static capacity of ball bearings?
(where d = roller diameter, L = roller length)
a. KdLZ / 5
b. Kd2Z / 5
c. K2dL / 5Z
d. 5 Kd / Z
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20) The expected rating life of roller bearings rotating at 1000 r.p.m. is 30000 hours and equivalent dynamic load of 4000 N acts on it. What is the basic dynamic capacity of the bearing?
a. 26000.12 N
b. 30000.23 N
c. 37900.22 N
d. 48657.61 N
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21) What is the effect of large diametral quotient on worm and worm wheel?
a. Strength and rigidity of worm shaft is high
b. Efficiency of worm shaft increases
c. Worm shaft becomes weaker
d. All of the above
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22) Which of the following relations is true?
(where nw = worm speed, ng = worm gear speed, zg = number of teeth on worm gear, zw = number of starts on worm)
a. nw α (1/zg)
b. nw / ng = zg /zw
c. nw / ng = zw /zp
d. nw zg = ng zw
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23) The shortest distance between worm gear and axes of the worm is given as ______________
a. m (zw + zg) / q
b. m (zw + zg) / 2
c. m (q + zg) / 2
d. √m (q + zg) / 2
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24) A standard worm gear pair is designated as 4/40/10/8, what does number 10 in it indicate?
a. Number of starts on worm
b. Diametral quotient
c. Centre distance
d. Module
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25) A worm gear pair is designated as 1/30/10/8. What is the face width of the worm gear?
a. 30 mm
b. 53.07 mm
c. 58.4 mm
d. 62.3 mm
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26) Which of the following belts is used when axes of two shafts are perpendicular and intersecting?
a. Open belt drive
b. Cone pulley drive
c. Quarter turn belt drive with guide pulley
d. Stepped pulley drive with guide pulley
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27) Friction ply used in multiple-ply belts is made of ___________
a. polyester cords
b. polyamide strips
c. synthetic strips
d. all of the above
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28) Two pulleys of an open belt drive A and B transmit power of 100 kW from pulley A running at 1000 r.p.m to pulley B at 500 r.p.m. If diameter of pulley A is 150 mm and 3% is the slip at operating conditions then what is the diameter of pulley B? (Assume thickness of belt = 12 mm)
a. 300.22 mm
b. 326.28 mm
c. 302.28 mm
d. 317.13 mm
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29) A flat belt transmits power of 20 kW when the velocity of the belt is 30 m/s. What will be the initial tension in the belt if 230 N is the centrifugal tension in the belt and F1 / F2 =2.5?
a. 1007.77 N
b. 1000.2 N
c. 908.23 N
d. 896.15 N
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30) A flat belt pulley has centre distance between two pulleys as 1000 mm. If diameters of two pulleys are 600 mm and 300 mm, what is the length of belt?
a. 2436.21 mm
b. 3003 mm
c. 3256.5 mm
d. 3436 mm
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31) What is the shear stress in fluid per unit velocity gradient called as?
a. Absolute viscosity
b. Dynamic viscosity
c. Both a. and b.
d. None of the above
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32) What is the S.I unit of kinematic viscosity?
a. N-s / m2
b. m2 / s
c. N-s m2
d. None of the above
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33) Which of the following is not a property of lubricants?
a. High specific heat
b. High flash point
c. Low pour point
d. Low oxidation stability
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34) Mass of ___________ required to neutralize one gram of lubricating oil is called as neutralization number.
a. potassium hydroxide
b. calcium hydroxide
c. magnesium hydroxide
d. None of the above
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35) Which of the following parameters in Petroff's equation f = 2π2 (μns/p) (r/c) is/are dimensionless?
a. r/c
b. μns/p
c. Both a. and b.
d. None of the above
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