In designing a key, it is assumed that the distribution of forces along the length of key
Varies linearly
Is uniform throughout
Varies exponentially, being more at the torque-input end
Varies exponentially, being less at the torque-input end
Correct Answer :
B. Is uniform throughout
Related Questions
The angle of twist of shaft is
Directly proportional to (shaft diameter)²
Inversely proportional to (shaft diameter)²
Directly proportional to (shaft diameter)⁴
Inversely proportional to (shaft diameter)⁴
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
Three different weights fall from a certain height under vacuum. They will take
Same time to reach earth
Times proportional to weight to reach earth
Times inversely proportional to weight to reach earth
None of the above
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
A sliding bearing which operates without any lubricant present, is called
Zero film bearing
Boundary lubricated bearing
Hydrodynamic lubricated bearing
Hydrostatic lubricated bearing
The efficiency of a riveted joint is equal to
Pt /P
Ps /P
Pc /P
Least of Pt, Ps and Pc/P
The suitable material for belt in agricultural machinery is
Leather
Rubber
Cotton duck
Balata gum
The number of slots in a 25 mm castle nut is
8
4
2
6
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above
The stiffness of a closely coiled helical spring subjected to an axial load W is equal to (where G = Modulus of rigidity, and n = Number of active coils)
Gd⁴/ 8D3n
Gd3/ 8D3n
Gd⁴/ 4D3n
Gd⁴/ 8D²n
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
According to I.B.R., the distance between the rows of rivets, for equal number of rivets in more than one row for lap joint or butt joint (chain riveting) shall not be less than
d
1.5 d
2d
2.5 d
Stress concentration factor is defined as the ratio of
Maximum stress to the endurance limit
Nominal stress to the endurance limit
Maximum stress to the nominal stress
Nominal stress to the maximum stress
In levers, leverage is the ratio of
Load lifted to the effort applied
Mechanical advantage to the velocity ratio
Load arm to the effort arm
Effort arm to the load arm
A hollow saddle key is
A taper key which fits half in the key way of hub and half in the key way of shaft
A taper key which fits in a key way of the hub and is flat on the shaft
A taper key which fits in a key way of the hub and the bottom of the key is shaped to fit the curved surface of the shaft
Provided in pairs at right angles and each key is to withstand torsion in one direction only
The stress which vary from a minimum value to a maximum value of the same nature (i.e. tensile or compressive) is called
Repeated stress
Yield stress
Fluctuating stress
Alternating stress
Rankine's theory is used for
Brittle materials
Ductile materials
Elastic materials
Plastic materials
In case of V-belt drive
The belt should touch the bottom of groove in the pulley
The belt should not touch the bottom of groove in the pulley
The belt should not touch the sides of groove in the pulley
None of the above
A tap bolt
Has a head on one end and a nut fitted to the other
Has head at one end and other end fits into a tapped hole in the other part to be joined
Has both the ends threaded
Has pointed threads
In cylindrical cams, the follower moves
In a direction perpendicular to the cam axis
In a direction parallel to the cam axis
In any direction irrespective of cam axis
Along the cam axis
In unilateral system of tolerance, the tolerance is allowed on
Both sides of the actual size
One side of the actual size
One side of the nominal size
Both sides of the nominal size
For a square key made of mild steel, the shear and crushing strength are related as
Shear strength is equal to crushing strength
Shear strength is greater than crushing strength
Shear strength is less than crushing strength
None of the above
According to I.B.R., the efficiency of a triple riveted butt joint with double straps of unequal width (5 rivets per pitch length) should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
The connecting rod bolts are tightened up so that tightening stress
Is just sufficient to hold parts together
Approaches yield point
Is 50% of yield point
Is about yield point divided by safety factor
Fibrous fracture occurs in
Ductile material
Brittle material
Elastic material
Hard material
If T is the actual number of teeth on a helical gear and φ is the helix angle for the teeth, then formative number of teeth is written as
T sec3φ
T sec²φ
T/sec3φ
T cosecφ
The connecting rod bolts are tightened up with initial tension greater than the external load so that
Joint may not open up
Bolts are weakest elements
The resultant load on the bolt would not be affected by the external cyclic load
Bolts will not loosen during service
According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
d = t
d = 1.6 t
d = 2t
d = 6t
For circumferential joint in boilers, the type of joint used is
Butt joint with single cover plate
Butt joint with double cover plate
Lap joint with one ring overlapping the other
Any one of the above
According to Indian standards, the diameter of rivet hole is made larger than the basic size of rivet by
0.5 mm upto rivet diameter of 24 mm
1 mm for rivet diameter from 27 mm to 36 mm
2 mm for rivet diameter from 39 mm to 48 mm
All of the above