Elements of Machine Design-06

  1. Fundamentals of design
  2. Design of joints, levers and offset links
  3. Design of shafts, keys and couplings
  4. Design of power screws
  5. Design of springs
  6. Design of bolted and welded joints
  7. Selection of anti-friction bearings and gears

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1   If T₁ and T₂ are the tensions on the tight and slack sides of the belt respectively, and Tc is the centrifugal tension, then initial tension in the belt is equal to
    (A)   T₁ – T₂ + Tc
    (B)   T₁ + T₂ + Tc
    (C)   (T₁ – T₂ + Tc)/2
    (D)   (T₁ + T₂ + Tc)/2
[showhide type=”button7c1″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
2   Which of the following is a power transmitting element?
    (A)   Nuts and bolts
    (B)   Sprockets and chains
    (C)   Axles
    (D)   All of the above
[showhide type=”button7c2″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
3   The shaft directly connected to the power source is called as ______
    (A)   Line shaft
    (B)   Counter shaft
    (C)   Both A and B
    (D)   None of the above
[showhide type=”button7c3″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
4   Which of the following is a machine shaft?
    (A)   Line shaft
    (B)   Counter shaft
    (C)   Crankshaft
    (D)   All of the above
[showhide type=”button7c4″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
5   Which of the following statements is/are true?
    (A)   Jaw clutch is a positive clutch
    (B)   The power transmitting capacity of a friction clutch is inversely proportional to the coefficient of friction between contacting surfaces
    (C)   Driving and driven plates in friction clutches are held together due to radial force applied by the helical springs
    (D)   All of the above
[showhide type=”button7c5″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
6   A flange coupling is used
    (A)   For intersecting shafts
    (B)   For collinear shafts
    (C)   For small shafts rotating at slow speeds
    (D)   For parallel shafts
[showhide type=”button7c6″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
7   While designing a flange coupling, care is taken so that
    (A)   Shaft is the weakest component
    (B)   Bolts are the weakest component
    (C)   Key is the weakest component
    (D)   The flange is the weakest component
[showhide type=”button7c7″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
8   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
[showhide type=”button7c8″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
9   A muff coupling is
    (A)   Rigid coupling
    (B)   Flexible coupling
    (C)   Shock absorbing coupling
    (D)   None of the above
[showhide type=”button7c9″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
10   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
[showhide type=”button7c10″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
11   A stud has
    (A)   Both ends threaded
    (B)   Threads in the mid portion of its length
    (C)   A hole drilled through for inserting locking pin
    (D)   A plane slotted head for the screw driver
[showhide type=”button7c11″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
12   The shaft length is increased by connecting two or more pieces of suitable lengths by
    (A)   Cotter joint
    (B)   Knuckle joint
    (C)   Bolted joints
    (D)   Keys and couplings
[showhide type=”button7c12″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
13   Spot the odd one out
    (A)   Muff coupling
    (B)   Flange coupling
    (C)   Split coupling
    (D)   Bushed pin type coupling
[showhide type=”button7c13″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
14   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
[showhide type=”button7c14″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
15   For a flanged coupling, the diameter of bolts, ‘d’ is worked out from the relation (if ‘D’ is the diameter of the shaft and ‘n’ is the number of bolts)
    (A)   d=0.5D/ √(n)
    (B)   d=0.25D/ √(n)
    (C)   d=0.75D/ √(n)
    (D)   d=1.0D/ √(n)
[showhide type=”button7c15″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
16   The pin of a bushed pin coupling be checked for
    (A)   Compress stress
    (B)   Maximum principal stress
    (C)   Shear stress
    (D)   Bending stress
[showhide type=”button7c16″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
17   Identify the machine element given in the figure
    (A)   Muff coupling
    (B)   Oldham coupling
    (C)   Universal of Hooke’s coupling
    (D)   Flanged coupling
[showhide type=”button7c17″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
18   Identify the machine element given in the figure
    (A)   Muff coupling
    (B)   Oldham coupling
    (C)   Universal of Hooke’s coupling
    (D)   Flanged coupling
[showhide type=”button7c18″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
19   Identify the machine element given in the figure

    (A)   Muff coupling
    (B)   Oldham coupling
    (C)   Universal of Hooke’s coupling
    (D)   Flanged coupling
[showhide type=”button7c19″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
20   Identify the machine element given in the figure

    (A)   Muff coupling
    (B)   Oldham coupling
    (C)   Universal of Hooke’s coupling
    (D)   Flanged coupling
[showhide type=”button7c20″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
21   Oldham coupling is used to connect two shafts having intersecting axes.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button7c21″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
22   A machine started malfunctioning due to some issues with the coupling. The coupling emplaced in the machine was Oldham. The only coupling available in the workshop is Hooke’s coupling. So, Oldham coupling can be replaced by Hooke’s coupling.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button7c22″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
23   The coupling used to connect two shafts with large angular misalignment is:
    (A)   Flange coupling
    (B)   Oldham’s coupling
    (C)   Hooke’s joint
    (D)   None of the above
[showhide type=”button7c23″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
24   In a flange coupling, the keys are staggered at __________ along the circumference of the shafts in order to divide the weakening effect caused by key ways.
    (A)   90°
    (B)   135°
    (C)   160°
    (D)   180°
[showhide type=”button7c24″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
25   A shaft coupling should
    (A)   Be easy to connect or disconnect
    (B)   Transmit full power of the shaft
    (C)   Hold the shafts in perfect alignment
    (D)   All of these
[showhide type=”button7c25″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
26   Shaft coupling is used in machinery to
    (A)   Introduce mechanical flexibility
    (B)   Introduce protection against over loads
    (C)   Reduce the transmission of shock loads
    (D)   All of these
[showhide type=”button7c26″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
27   A tangent key is provided in pairs at right angles and each key is to withstand torsion in one direction only.
    (A)   Agree
    (B)   Disagree
[showhide type=”button7c27″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
28   A feather key transmits a turning moment and permits axial movement also.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button7c28″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
29   The thickness of key is usually taken equal to one-sixth of diameter of shaft.
    (A)   Yes
    (B)   No
[showhide type=”button7c29″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
30   The taper on a rectangular sunk key is
    (A)   1 in 16
    (B)   1 in 32
    (C)   1 in 48
    (D)   1 in 100
[showhide type=”button7c30″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
31   A key made from a cylindrical disc having segmental cross-section is known as
    (A)   Feather key
    (B)   Gib-head key
    (C)   Wood ruff key
    (D)   Flat saddle key
[showhide type=”button8c1″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
32   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
[showhide type=”button8c2″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
33   The taper on key is given on
    (A)   Bottom side only
    (B)   Top side only
    (C)   On both sides
    (D)   Any side
[showhide type=”button8c3″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
34   The main advantage of sunk key is that it is a _____ drive.
    (A)   Positive
    (B)   Negative
    (C)   Neutral
    (D)   None of the listed
[showhide type=”button8c4″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
35   Which of the following statement is correct?
    (A)   A parallel sunk key is a taperless key
    (B)   A parallel sunk key may be rectangular or square in cross-section
    (C)   A flat saddle key is a taper key which fits in a key way of the hub and is flat on the shaft
    (D)   All of the above
[showhide type=”button8c5″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
36   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
[showhide type=”button8c6″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
37   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
[showhide type=”button8c7″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
38   The standard length of the shaft is
    (A)   5 m
    (B)   6 m
    (C)   7 m
    (D)   All of these
[showhide type=”button8c8″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
39   A key way lowers
    (A)   The strength of the shaft
    (B)   The rigidity of the shaft
    (C)   Both the strength and rigidity of the shaft
    (D)   The ductility of the shaft
[showhide type=”button8c9″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
40   A tapered key which fits in a key way in the hub and is flat on the shaft, is known as
    (A)   Feather key
    (B)   Gib-head key
    (C)   Wood ruff key
    (D)   Flat saddle key
[showhide type=”button8c10″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
41   A taper key which fits half in the key way of the hub and half in the key way of shaft, is known as
    (A)   Sunk key
    (B)   Flat saddle key
    (C)   Hollow saddle key
    (D)   Tangent key
[showhide type=”button8c11″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
42   A feather key is generally
    (A)   Loose in shaft and tight in hub
    (B)   Tight in shaft and loose in hub
    (C)   Tight in both shaft and hub
    (D)   Loose in both shaft and hub
[showhide type=”button8c12″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
43   Which of the following key is preferred for the condition when a large amount of impact type torque is to be transmitted in both directions of rotation?
    (A)   Woodruff key
    (B)   Feather key
    (C)   Gib-head key
    (D)   Tangent key
[showhide type=”button8c13″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
44   The type of stresses developed in the key is/are
    (A)   Shear stress alone
    (B)   Crushing stress alone
    (C)   Both shear and crushing stresses
    (D)   Shearing, crushing and bending stresses
[showhide type=”button8c14″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
45   A saddle key __________ power through frictional resistance only.
    (A)   Transmits
    (B)   Does not transmit
[showhide type=”button8c15″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
46   A tapered key that fits in a keyway in the hub and the bottom of which is shaped to fit the curved surface of the shaft is known as the hollow saddle key.
    (A)   Correct
    (B)   Incorrect
[showhide type=”button8c16″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
47   Two shafts A and B of solid circular cross-section are identical except for their diameters dA and dB. The ratio of power transmitted by the shaft A to that of shaft B is
    (A)   dA/dB
    (B)   (dA)2/(dB)2
    (C)   (dA)3/(dB)3
    (D)   (dA)4/(dB)4
[showhide type=”button8c17″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
48   A transmission shaft subjected to bending loads must be designed on the basis of
    (A)   Maximum normal stress theory
    (B)   Maximum shear stress theory
    (C)   Maximum normal stress and maximum shear stress theories
    (D)   Fatigue strength
[showhide type=”button8c18″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
49   Which of the following loading is considered for the design of axles?
    (A)   Bending moment only
    (B)   Twisting moment only
    (C)   Combined bending moment and torsion
    (D)   Combined action of bending moment, twisting moment and axial thrust
[showhide type=”button8c19″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
50   When a shaft is subjected to a bending moment M and a twisting moment T, then the equivalent twisting moment is equal to
    (A)   M + T
    (B)   M2+ T2
    (C)   SQRT(M2+T2)
    (D)   SQRT(M2-T2)
[showhide type=”button8c20″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
51   The maximum shear stress theory is used for
    (A)   Brittle materials
    (B)   Ductile materials
    (C)   Plastic materials
    (D)   Non-ferrous materials
[showhide type=”button8c21″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
52   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
[showhide type=”button8c22″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
53   When the shaft is subjected to pure bending moment, the bending stress is given by?
    (A)   32M/πd3
    (B)   16M/πd3
    (C)   8M/πd3
    (D)   None of the listed
[showhide type=”button8c23″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
54   When a shaft is subjected to combined twisting moment (T) and bending moment (M), then the equivalent twisting moment is equal to
    (A)   1/2 √ (M2+T2)
    (B)   √(M2+T2)
    (C)   1/2 (M+ √(M2+T2))
    (D)   M+ √(M2+T2)
[showhide type=”button8c24″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
55   A circular shaft can transmit a torque of 5 kN-m. If the torque is reduced to 4 kN-m, then the maximum value of bending moment that can be applied to the shaft is
    (A)   1 kN-m
    (B)   2 kN-m
    (C)   3 kN-m
    (D)   4 kN-m
[showhide type=”button8c25″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
56   The angle of twist of shaft is
    (A)   Directly proportional to (shaft diameter)2
    (B)   Inversely proportional to (shaft diameter)2
    (C)   Directly proportional to (shaft diameter)4
    (D)   Inversely proportional to (shaft diameter)4
[showhide type=”button8c26″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
57   If T=torque, θ=angle of twist, J=polar moment of inertia, G=modulus of rigidity, then the torsional rigidity is given as
    (A)   T/θ
    (B)   Gθ
    (C)   GJ
    (D)   θ
[showhide type=”button8c27″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
58   Which of the following is not an assumption in derivation of torsion equation?
    (A)   Circular shaft remains circular after twisting
    (B)   Plane section of the shaft remain plan after twisting
    (C)   Material of shaft is isotropic
    (D)   Angle of twist is proportional to radius
[showhide type=”button8c28″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
59   A shaft
    (A)   Is always subjected to pure torsion
    (B)   Combination of M & T but no end thrust
    (C)   Combination of torque & end thrust but no bending moment
    (D)   May be subjected to a combination of M, T and end thrust
[showhide type=”button8c29″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
60   For same weight, same material, same length
    (A)   Solid shaft is always stronger than a hollow shaft
    (B)   Sold shaft is always weaker than the hollow shaft and strength ratio will depend upon Do/Di of hollow shaft
    (C)   Strengths of both the shafts are equal
    (D)   None of the above
[showhide type=”button8c30″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
61   Magnitude of shear stress induced in a shaft due to applied torque varies from
    (A)   Maximum at center to zero at circumference
    (B)   Maximum at center to minimum (not-zero) at circumference
    (C)   Zero at center to maximum at circumference.
    (D)   Minimum (not zero) at center to maximum at circumference
[showhide type=”button9c1″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
62   Maximum shear stress of a solid shaft is given by
    (A)   16T/πd
    (B)   16T/πd2
    (C)   16T/πd3
    (D)   16T/πd4
[showhide type=”button9c2″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
63   The angle of twist is ————- proportional to the twisting moment.
    (A)   Directly
    (B)   Inversely
    (C)   Indirectly
    (D)   Reversely
[showhide type=”button9c3″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
64   The polar moment of inertia of a solid circular shaft of diameter (d) is
    (A)   πd2/16
    (B)   πd3/32
    (C)   πd4/32
    (D)   πd4/64
[showhide type=”button9c4″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
65   The polar moment of inertia of a hollow shaft of outer diameter (D) and inner diameter (d) is given by.
    (A)   π (D3-d3) /32
    (B)   π(D4-d4) /32
    (C)   π(D4-d4) /16
    (D)   π(D4-d4/d) /32
[showhide type=”button9c5″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
66   For same length, same material, same torque transmitted
    (A)   Weight of solid shaft is less than weight of hollow shaft
    (B)   Weight of solid shaft is more than weight of hollow shaft
    (C)   Weight of hollow and solid shafts will be same
    (D)   Sometime more sometime less
[showhide type=”button9c6″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
67   Two shafts in torsion will have equal strength if
    (A)   Only diameter of the shafts is same
    (B)   Only angle of twist of the shaft is same
    (C)   Only material of the shaft is same
    (D)   Only torque transmitting capacity of the shaft is same
[showhide type=”button9c7″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
68   A Shaft is said to be in pure torsion if
    (A)   Turning moment is applied at one end and the other end is free
    (B)   Turning force is applied at one end and the other end is free
    (C)   Two opposite turning moments are applied to the shaft
    (D)   Combination of torsional load and bending load is applied to the shaft
[showhide type=”button9c8″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
69   In power transmission equation, P=2πNT/60
    (A)   P is in kW and T is maximum torque
    (B)   P is in NM/sec and T is maximum torque
    (C)   P is in NW/sec and T is mean torque
    (D)   P is in kW and T is mean torque
[showhide type=”button9c9″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
70   Which material is suitable for shaft material?
    (A)   High speed steel
    (B)   Stainless steel or high carbon steel
    (C)   Grey cast iron
    (D)   Steel having approx. 0.4% carbon 0.8% manganese
[showhide type=”button9c10″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
71   If diameter of a shaft is doubled the power transmitted capacity will be
    (A)   Either twice of half
    (B)   Four times
    (C)   Eight times
    (D)   Same
[showhide type=”button9c11″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
72   Strength of a shaft
    (A)   Is equal to maximum shear stress in the shaft at the time of elastic failure
    (B)   Is equal to maximum shear stress in the shaft at the time of rupture
    (C)   Is equal to torsional rigidity
    (D)   Is ability to transmit twisting moment
[showhide type=”button9c12″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
73   Which of the following is not designed under torsion equation?
    (A)   Spindle
    (B)   Axle
    (C)   Low-cost shaft
    (D)   Shaft with variable diameter
[showhide type=”button9c13″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
74   Which of the following is incorrect?
    (A)   In torsion equation, we use mean torque
    (B)   In torsion equation, we use maximum torque
    (C)   Many shafts are designed under combined bending and torsion load
    (D)   Shafts are also designed for torsional rigidity
[showhide type=”button9c14″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
75   Which of the following is incorrect?
    (A)   In a solid shaft maximum shear stress occurs at radius = radius of shaft
    (B)   In a solid shaft maximum shear stress occurs at the center
    (C)   In a hollow shaft maximum shear stress occurs at outer radius
    (D)   In a hollow shaft minimum shear stress occurs at inner radius
[showhide type=”button9c15″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
76   The following option is correct
    (A)   There is neither advantage nor disadvantage in transmitting power at high speed
    (B)   There is advantage in transmitting power at high speeds
    (C)   There is disadvantage in transmitting power at high speeds
    (D)   There is advantage in transmitting power at high speed provided shafts are made of high-speed steel
[showhide type=”button9c16″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
77   The shaft is always stepped with ________ diameter at the middle portion and __________ diameter at the shaft ends.
    (A)   Minimum, maximum
    (B)   Maximum, minimum
    (C)   Minimum, minimum
    (D)   Zero, infinity
[showhide type=”button9c17″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
78   ______ is used for a shaft that supports rotating elements like wheels, drums or rope sleeves.
    (A)   Spindle
    (B)   Axle
    (C)   Shaft
    (D)   None of the listed
[showhide type=”button9c18″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
79   Counter shaft is a secondary shaft.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button9c19″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
80   Which of the following act on shafts?
    (A)   Torsional moment
    (B)   Bending Moment
    (C)   Both torsional and bending
    (D)   None of the mentioned
[showhide type=”button9c20″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
81   When the shaft is subjected to pure torsional moment, the torsional stress is given by?
    (A)   None of the listed
    (B)   32M/πd3
    (C)   16M/πd3
    (D)   8M/πd3
[showhide type=”button9c21″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
82   Which property is not required for shaft materials?
    (A)   High shear and tensile strength
    (B)   Good machinability
    (C)   High fatigue strength
    (D)   Good castability
[showhide type=”button9c22″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
83   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
[showhide type=”button9c23″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
84   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
[showhide type=”button9c24″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
85   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
[showhide type=”button9c25″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
86   A shaft is designed on the basis of rigidity and stiffness.
    (A)   Correct
    (B)   Incorrect
[showhide type=”button9c26″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
87   Identify the machine element

    (A)   Hollow shaft
    (B)   Stepped shaft
    (C)   Splined shaft
    (D)   None of the above
[showhide type=”button9c27″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
88   Which of the following are functions of bearings?
    (A)   Ensure free rotation of shaft with minimum friction
    (B)   Holding shaft in a correct position
    (C)   Transmit the force of the shaft to the frame
    (D)   All of the listed
[showhide type=”button9c28″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: D [/showhide]
89   A coupling is a mechanical device that temporarily joins two rotating shafts to each other.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button9c29″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
90   Oldham coupling is used to connect two shafts having intersecting axes.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button9c30″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
91   A muff coupling is connecting two shafts. The torque involved is 650N-m. The shaft diameter is 45mm with length and breadth of the key being 14mm and 80mm respectively. Find the shear stress induced in the key.
    (A)   30.2N/mm2
    (B)   25.8N/mm2
    (C)   34.4N/mm2
    (D)   None of the listed
[showhide type=”button10c1″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
92   A muff coupling is connecting two shafts. The torque involved is 650N-m. The shaft diameter is 45mm with length and height of the key being 14mm and 80mm respectively. Find the compressive stress induced in the key.
    (A)   70.1 N/mm²2
    (B)   51.6N/mm2
    (C)   45.5N/mm2
    (D)   None of the listed
[showhide type=”button10c2″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
93   Calculate the force acting on each pin in flexible coupling if torque transmitted is 397N-m and PCD=120mm with number of pins 6.
    (A)   1400.3N
    (B)   1102.8N
    (C)   1320.3N
    (D)   None of the listed
[showhide type=”button10c3″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
94   Entire torque is transmitted by friction in the clamp coupling.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button10c4″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
95   Does shaft have to be shifted in axial direction to remove clamp coupling.
    (A)   Yes
    (B)   No
[showhide type=”button10c5″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
96   If shaft diameter is 40mm, calculate the diameter of sleeves in clamp coupling.
    (A)   100mm
    (B)   80mm
    (C)   60mm
    (D)   40mm
[showhide type=”button10c6″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
97   If shaft diameter is 40mm, calculate the length of sleeves in clamp coupling.
    (A)   80mm
    (B)   140mm
    (C)   100mm
    (D)   120mm
[showhide type=”button10c7″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]
98   If 8 bolts are emplaced in a clamp coupling with shaft diameter 80mm d, calculate the tensile force on each bolt if coefficient of friction is 0.3 and torque transmitted is 4000N-m.
    (A)   51234.4N
    (B)   45968.3N
    (C)   41666.7N
    (D)   None of the above
[showhide type=”button10c8″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: C [/showhide]
99   If 8 bolts are emplaced in a clamp coupling with shaft diameter 80mm d, calculate the diameter of each bolt if coefficient of friction is 0.3 and torque transmitted is 4000N-m. Permissible tensile stress is 80N/mm².
    (A)   27mm
    (B)   25mm
    (C)   23mm
    (D)   21mm
[showhide type=”button10c9″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: A [/showhide]
100   Power is transmitted by flange only in rigid flange coupling.
    (A)   TRUE
    (B)   FALSE
[showhide type=”button10c10″ more_text=”Show Answer” less_text=”Hide Answer”] Answer: Option: B [/showhide]

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