For a shaft diameter of 100 mm, the number of bolts in a flange coupling should be
4
6
8
10
Correct Answer :
A. 4
Related Questions
Belt slip may occur due to
Heavy load
Loose belt
Driving pulley too small
All of the above
The minimum number of teeth on the pinion which will mesh with any gear without interference for 20° full depth involute teeth will be
12
14
18
24
Two shafts of the same length and material are joined in series. If the ratio of their diameters is 2, then the ratio of their angles of twist will be
2
4
8
16
The power transmitted by the belt drive can be increased by
Increasing the initial tension in the belt
Dressing the belt to increase the coefficient of friction
Increasing wrap angle by using idler pulley
All of the above methods
If P1 and P2 are the tight and slack side tensions in the belt, then the initial tension Pi (neglecting centrifugal tension) will be equal to
P1 - P2
P1 + P2
2 × (P1 + P2)
[2 × (P1 + P2)] + Pc Where Pc is centrifugal tension
In an oil lubricated journal bearing, the coefficient of friction between the journal and the bearing
Remains constant at all speeds
Is minimum at zero speed and increases monotonically with increase in speed
Is maximum at zero speed and decreases monotonically with increase in speed
Becomes minimum at an optimum speed and then increases with further increase in speed
For a bevel gear having the pitch angle θ, the ratio of formative number of teeth (TE) to actual number of teeth (T) is
1/sinθ
1/cosθ
1/tanθ
sinθ cosθ
In worm, gears, pitch lead angle is
Half the angle between two inclined faces in axial plane
The angle between the tangent to the pitch helix and the plane of rotation
The angle between the tangent to the pitch helix and an element of the cylinder
None of the above
In standard taper roller bearings, the angle of taper of outer raceway is
5°
8°
15°
25°
Tearing resistance required to tear off the plate per pitch length is (where p = Pitch of rivets, d = Dia. of rivet hole, and σt = Permissible tensile stress for plate material)
p.d.σt
p.t.σt
(p - d) σt
(p - d) t.σt
A self locking screw has
Fine threads
Course threads
Coefficient of friction is greater than tangent of load angle
Hole for inserting split pin
If the centre distance of the mating gears having involute teeth is varied within limits, the velocity ratio.
Increases
Decreases
Remains unchanged
None of these
A plate with an elliptical hole in the centre, with semi-major axis (A) perpendicular to the direction of loading and semi-minor axis (b) along the direction of loading, is subjected to a pull P. The maximum stress induced at the edge of the hole is equal to (where σ = Stress for a plate with no hole i.e. nominal stress)
σ [1 + (b/2a)]
σ [1 + (2a/b)]
σ [1 + (b/3a)]
σ [1 + (3a/b)]
For standard coarse threads of nut, the threads will be as strong in failure by shear as the bolt in tension, if the height of nut (h) is approximately
0.4 times
0.6 times
0.7 times
0.8 times
A connecting rod is designed as a
Long column
Short column
Strut
All of these
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
The property of a material which enables it to be drawn into wires with the application of a tensile force, is called
Plasticity
Elasticity
Ductility
Malleability
When carbon in the cast iron is principally in the form of graphite, the cast iron will be of
Brown colour
Yellow colour
White colour
Grey colour
A connecting rod should be
Strong in buckling about X-axis
Strong in buckling about Y-axis
Equally strong in buckling about X-axis and Y-axis
Any one of the above
In helical gears, the right hand helixes on one gear will mesh __________ helixes on the other gear.
Right hand
Left hand
Both A and B
None of these
The pipe joint mostly used for pipes carrying water at low pressures is
Socket joint
Nipple joint
Union joint
Spigot and socket joint
The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be
Same in both cases
2 times more
3 times more
4 times more
A bench vice has following type of threads
Metric
Square
Buttress
Acme
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
1 kN-m
2 kN-m
3 kN-m
4 kN-m
The lower deviation is the algebraic difference between the
Actual size and the corresponding basic size
Maximum limit and the basic size
Minimum limit and the basic size
None of the above
Which of the following statement is correct, for two shafts connected in parallel?
Torque in each shaft is the same
Shear stress in each shaft is the same
Angle of twist of each shaft is the same
Torsional stiffness of each shaft is the same
Idler pulley is used for
Increasing velocity ratio
For applying tension
Changing the direction of motion of belt
All of these
The endurance limit in shear of carbon steel can be obtained by multiplying the endurance limit in flexure by a factor of
0.45
0.55
0.65
0.75
An open belt drive is used when
Shafts are arranged at right angles and rotate in one definite direction
Shafts are arranged parallel and rotate in the opposite directions
Shafts are arranged parallel and rotate in the same directions
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft
In the calculation of induced shear stress in helical springs, the Wahl's stress factor is used to take care of
Combined effect of transverse shear stress and bending stress in the wire
Combined effect of bending stress and curvature of the wire
Combined effect of transverse shear stress and curvature of wire
Combined effect of torsional shear stress and transverse shear stress in the wire