- Fundamentals of design
- Design of joints, levers and offset links
- Design of shafts, keys and couplings
- Design of power screws
- Design of springs
- Design of bolted and welded joints
- Selection of anti-friction bearings and gears
Design of shafts, keys and couplings
1 If shaft diameter is 60mm, how many bolts are recommended for rigid flange coupling?- (A) 2
- (B) 3
- (C) 4
- (D) 6
2 Determine the diameter of the bolts used in rigid flange coupling if transmitted torque is 270N-m, pitch circle diameter=125mm and four bolts are emplace in the coupling. Permissible shear stress in the bolts is 70N/mm².
- (A) 3.8mm
- (B) 3.6mm
- (C) 4.4mm
- (D) 4mm
3 The hub is treated as a solid shaft while calculating torsional shear stress in the hub.
- (A) TRUE
- (B) FALSE
4 Find the shear stress in a flange at the junction of hub in rigid flanged coupling if torsional moment is 2980N-m and diameter of hub being 125mm. Also the thickness of flange is 25mm.
- (A) 6.77N/mm2
- (B) 10.24N/mm2
- (C) 4.84N/mm2
- (D) 4.22N/mm2
5 Which property is not required for shaft materials?
- (A) High shear and tensile strength
- (B) Good machinability
- (C) High fatigue strength
- (D) Good cast ability
6 When a solid shaft is subjected to torsion, the shear stress —– induced in the shaft at its center is
- (A) Minimum
- (B) Zero
- (C) Maximum
- (D) Average
7 The design of shafts made of brittle materials is based on
- (A) Guest’s theory
- (B) Rankine’s theory
- (C) St. Venant’s theory
- (D) Von Mises theory
8 When a shaft is subjected to a twisting moment, every cross section of the shaft will be under
- (A) Tensile stress
- (B) Compressive stress
- (C) Shear stress
- (D) Bending stress
9 The product of the tangential force acting on the shaft and its distance from the axis of the shaft (i.e., the radius of the shaft) is known as
- (A) Bending moment
- (B) Twisting moment
- (C) Torsional rigidity
- (D) Flexural rigidity
10 A sunk key fits in the keyway of the —– only.
- (A) Hub
- (B) Sleeve
- (C) Both hub and sleeve
- (D) Neither hub nor sleeve
11 Hollow saddle key is superior to flat saddle key as far as power transmitting capability is concerned.
- (A) TRUE
- (B) FALSE
12 The main advantage of sunk key is that it is a —– drive.
- (A) Positive
- (B) Negative
- (C) Neutral
- (D) None of the listed
13 Woodruff key permits —– movement b/w shaft and the hub.
- (A) Axial
- (B) Radial
- (C) Eccentric
- (D) None of the listed
14 Determine the length of Kennedy key required to transmit 1200N-m and allowable shear in the key is 40N/mm². The diameter of shaft and width of key can be taken as 40mm and 10mm respectively.
- (A) 49mm
- (B) 36mm
- (C) 46mm
- (D) 53mm
15 A universal coupling used to connect two shafts
- (A) Which are not in exact alignment
- (B) Which are perfectly aligned
- (C) Whose axes intersect at a small angle
- (D) Have lateral misalignment
16 A flange coupling is used to connect two shafts
- (A) Which are perfectly aligned
- (B) Which are not in exact alignment
- (C) Have lateral misalignment
- (D) Whose axes intersect at a small
17 The taper on key is given on
- (A) Bottom side only
- (B) Top side only
- (C) On both sides
- (D) Any side
18 Which of the following statement is wrong?
- (A) A key is used as a temporary fastening
- (B) A key is subjected to tensile stresses
- (C) A key is always inserted parallel to the axis of the shaft
- (D) A key prevents relative motion between the shaft and boss of the pulley
19 In designing a key, it is assumed that the distribution of forces along the length of the key
- (A) Varies linearly
- (B) Is uniform throughout
- (C) Varies exponentially, being more at the torque-input end
- (D) Varies exponentially, being less at the torque-input end
20 The taper on a rectangular sunk key is
- (A) 1 in 16
- (B) 1 in 32
- (C) 1 in 48
- (D) 1 in 100
21 The type of stresses developed in the key is/are
- (A) Shear stress alone
- (B) Bearing stress alone
- (C) Both shear and bearing stresses
- (D) Shearing, bearing and bending stresses
22 A saddle key ———- power through frictional resistance only
- (A) Transmits
- (B) Does not transmit
23 The thickness of key is usually taken equal to one-sixth of diameter of shaft.
- (A) Yes
- (B) No
24 Does a keyway slot in shaft reduce the strength of shaft?
- (A) Yes
- (B) No
25 A tapered key which fits in a key way in the hub and if flat on the shaft, is known as
- (A) Feather key
- (B) Gib-head key
- (C) Wood ruff key
- (D) Flat saddle key
26 When the pulley or other mating piece is required to slide along the shaft, a ———- sunk key is used.
- (A) Rectangular
- (B) Square
- (C) Parallel
27 —- is used to transmit the torque between the shaft and the adjoining machine part like gear, pulley or sprocket.
- (A) Bearing
- (B) Key
- (C) Power screw
- (D) Any of the above
28 Key used when the key is to be removed frequently.
- (A) Sunk Key
- (B) Feather Key
- (C) Woodruff Key
- (D) Gib Head Key
29 Most common key used for industrial purposes.
- (A) Rectangular key
- (B) Square sunk key
- (C) Round key
- (D) Spline key
30 Best use case for round key
- (A) High power transmission
- (B) Low power transmission
- (C) High load capacity
31 Following are the main types of couplings.
- (A) Rigid
- (B) Flexible
- (C) All of the above
- (D) None of the above
32 Which of the following elements is used to connect two shafts?
- (A) Clutch
- (B) Brakes
- (C) Couplings
- (D) None of the above
33 A muff coupling is.
- (A) Rigid coupling
- (B) Flexible coupling
- (C) Shock absorbing coupling
- (D) None of the above
34 A bushed-pin type flange coupling is used.
- (A) For intersecting shafts
- (B) When the shafts are not in exact alignment
- (C) For small shafts rotating at slow speeds
- (D) For parallel shafts
35 A universal coupling is used to connect two shafts.
- (A) Which are not in exact alignment
- (B) Which are perfectly aligned
- (C) Whose axes intersect at a small angle
- (D) Have lateral misalignment
36 A flange coupling is used to connect two shafts.
- (A) Which are perfectly aligned
- (B) Which are not in exact alignment
- (C) Have lateral misalignment
- (D) Whose axes intersect at a small angle
37 The sleeve or muff coupling is designed as a.
- (A) Dun cylinder
- (B) Hollow shaft
- (C) Solid shaft
- (D) Thick cylinder
38 A Flange Coupling Is.
- (A) Used for non-collinear shafts
- (B) Used for collinear shafts
- (C) Flexible
- (D) Used only on small shafts rotating at slow speeds
39 Actual stress in the bolts of a flanged coupling of a shaft will be.
- (A) More than the designed strength
- (B) Less than the designed strength
- (C) Neither more nor less than the designed strength
- (D) None
40 The flanges of a flange coupling are coupled together by means of bolts and their number depends upon.
- (A) Length of the shaft
- (B) Material of the shaft
- (C) Diameter of the shaft
- (D) Rotational speed of the shaft
41 Which types of coupling used to connect shafts, whose axis are parallel but not in one line?
- (A) Muff coupling
- (B) Flexible coupling
- (C) Oldham’s coupling
- (D) Flange coupling
42 Universal coupling is used to connect two shafts
- (A) Which are perfectly aligned
- (B) Which are not in exact alignment
- (C) Have lateral misalignment
- (D) Whose axes intersect at a small angle
43 The universal coupling is a type of ————
- (A) Flexible coupling
- (B) Rigid coupling
- (C) Both A and B
- (D) None of the above
44 Which of the following coupling is used to connect two shafts which have both lateral and angular misalignment?
- (A) Bush pin type coupling
- (B) Universal coupling
- (C) Oldham coupling
- (D) All of these
45 Which of the following is rigid coupling?
- (A) Muff coupling
- (B) Split muff coupling
- (C) Flange coupling
- (D) All of the above
46 Which Coupling is modification of Flange coupling?
- (A) Bush Pin type
- (B) Oldham
- (C) Universal
- (D) Muff
47 The Coupling Bolts are known as
- (A) Muff
- (B) Nuts
- (C) Pins
- (D) All of above
48 What are the types of Flange Coupling?
- (A) Protected
- (B) Unprotected
- (C) Marine
- (D) All of the above
49 Which of the following is not type of flexible Coupling?
- (A) Oldham Coupling
- (B) Universal Coupling
- (C) None
- (D) Bushed pin type
50 Which Coupling is simpler in design?
- (A) Muff or Sleeve
- (B) Flange
- (C) Bushed pin type
- (D) All above
51 Muff Coupling consist of a hollow cylinder called as
- (A) Shaft
- (B) Muff
- (C) Sleeve
- (D) Both B and C
52 Magnitude of shear stress induced in a shaft due to applied torque varies from
- (A) Maximum at centre to zero at circumference
- (B) Maximum at centre to minimum (not-zero) at circumference
- (C) Zero at centre to maximum at circumference.
- (D) Minimum (not zero) at centre to maximum at circumference
53 The variation of shear stress in a circular shaft subjected to torsion is
- (A) Linear
- (B) Parabolic
- (C) Hyperbolic
- (D) Uniform
54 The relation governing the torsional torque in circular shafts is
- (A) T/r=τ/l=Gθ/J
- (B) T/J=τ/r=Gθ/l
- (C) T/J=τ/l=Gθ/r
- (D) T/l=τ/r=Gθ/J
55 Torsional rigidity of a shaft is defined as
- (A) G/J
- (B) GJ
- (C) TJ
- (D) T/J
56 Torsional rigidity of a shaft is given by
- (A) Gl/θ
- (B) Tθ
- (C) Tl/θ
- (D) T/l
57 A solid shaft of same cross sectional area and of same material as that of a hollow shaft can resist
- (A) Less torque
- (B) More torque.
- (C) Equal torque
- (D) Unequal torque
58 Angle of twist of a circular shaft is given by
- (A) GJ/Tl
- (B) Tl/GJ
- (C) TJ/Gl
- (D) TG/Jl
59 Maximum shear stress of a solid shaft is given by
- (A) 16T/πd
- (B) 16T/πd2
- (C) 16T/πd3
- (D) 16T/πd4
60 The ratio of maximum bending stress to maximum shear stress on the cross section when a shaft is simultaneously subjected to a torque T and bending moment M,
- (A) T/M
- (B) M/T
- (C) 2T/M
- (D) 2M/T
61 Maximum shear stress in a hollow shaft subjected to a torsional moment is at the
- (A) Middle of thickness
- (B) At the inner surface of the shaft
- (C) At the outer surface of the shaft.
- (D) At the middle surface of the shaft
62 The ratio of strength of a hollow shaft to that of a solid shaft subjected to torsion if both are of the same material and of the same outer diameters, the inner diameter of hollow shaft being half of the outer diameter is
- (A) 15/16
- (B) 16/15
- (C) 7/8
- (D) 8/7
63 Ratio of diameters of two shafts joined in series is 2. If the two shafts have the same Material and the same length the ratio of their angles of twist is
- (A) 2
- (B) 4
- (C) 8
- (D) 16
64 Ratio of diameters of two shafts joined in series is 2. If the two shafts have the same material and the same length the ratio of their shear stresses is
- (A) 2
- (B) 4
- (C) 8
- (D) 16
65 For two shafts joined in series, the ————— in each shaft is same.
- (A) Shear stress
- (B) Angle of twist
- (C) Torque
- (D) Torsional stress
66 For two shafts joined in parallel, the ————— in each shaft is same.
- (A) Shear stress
- (B) Angle of twist
- (C) Torque
- (D) Torsional stress
67 The shafts are NOT made of
- (A) Mild steel
- (B) Alloy steel
- (C) Copper alloys
- (D) Cast iron
68 The shafts are designed on the basis of
- (A) Strength and rigidity
- (B) Ductility
- (C) Malleability
- (D) Resilience