According to I.B.R., the efficiency of a double riveted butt joint with double cover straps of equal width should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
Correct Answer :
C. 70 to 83 %
Related Questions
The cross-section of the arm of a bell crank lever is
Rectangular
Elliptical
I-section
Any one of these
When the belt is transmitting maximum power,
The tension in tight side is twice the centrifugal tension
The tension in slack side is equal to the centrifugal tension
The tension in tight side is thrice the centrifugal tension
None of the above
A feather key is generally
Loose in shaft and tight in hub
Tight in shaft and loose in hub
Tight in both shaft and hub
Loose in both shaft and hub
A 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
Is provided with pointed threads
The largest diameter of an external or internal screw thread is known as
Minor diameter
Major diameter
Pitch diameter
None of these
Two closely coiled helical springs with stiffness k₁ and k₂ respectively are connected in series. The stiffness of an equivalent spring is given by
(k₁ k₂)/ (k₁ + k₂)
(k₁ - k₂)/ (k₁ + k₂)
(k₁ + k₂)/ (k₁ k₂)
(k₁ - k₂)/ (k₁ k₂)
The bearings of heavy series have capacity ________ over the medium series.
20 to 30%
10 to 20%
30 to 40%
40 to 50%
Which of the following statement is wrong?
A key is used as a temporary fastening
A key is subjected to tensile stresses
A key is always inserted parallel to the axis of the shaft
A key prevents relative motion between the shaft and boss of the pulley
The resultant axial load on a bolt depends on
Initial tension
External load applied
Relative elastic yielding (springness) of the bolt and the connected member
All of the above
Tapered roller bearings can take
Axial load only
Both radial and axial loads and the ratio of these being greater than unity
Radial load only
Both radial and axial loads and the ratio of these being less than unity
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
When a nut is tightened by placing a washer below it, the bolt will be subjected to following type of loads
Compression
Tension
Shear
Combined loads
According to Indian standard specifications, 100 H6/g5 means that
Tolerance grade for the hole is 6 and for the shaft is 5
Tolerance grade for the shaft is 6 and for the hole is 5
Tolerance grade for the shaft is 4 to 8 and for the hole is 3 to 7
Tolerance grade for the hole is 4 to 8 and for the shaft is 3 to 7
According to I.B.R., the efficiency of a double riveted butt joint with double cover straps of equal width should be
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
The size of a cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve
When two helical springs of equal lengths are arranged to form a cluster spring, then
Shear stress in each spring will be equal
Load taken by each spring will be half the total load
Only A is correct
Both A and B is correct
The resultant axial load on a bolt depends upon
External load applied
Initial tension due to tightening of the bolt
Relative elastic yielding of the bolt and the connected members
All of the above
If a load W is applied instantaneously on a bar; Then the stress induced in bar will
Be independent of ratio of mass of load W to mass of bar (y)
Increase with increase in y
Decrease with decrease in y
Depend on other considerations
Two shafts A and B are made of the same material. The diameter of shaft A is twice as that of shaft B. The power transmitted by the shaft A will be __________ of shaft B.
Twice
Four times
Eight times
Sixteen times
The centrifugal tension in belts
Decreases the power transmitted
Increases the power transmitted
Increase the wrap angle
Increases the belt tension without increasing power transmission
A sliding bearing which operates without any lubricant present, is called
Zero film bearing
Boundary lubricated bearing
Hydrodynamic lubricated bearing
Hydrostatic lubricated bearing
The yield point in static loading is __________ as compared to fatigue loading.
Higher
Lower
Same
None of these
Belt slip may occur due to
Heavy load
Loose belt
Driving pulley too small
All of the above
In a belt drive, if the pulley diameter is doubled keeping the tension and belt width constant, then it will be necessary to
Increase the key length
Increase the key depth
Increase the key width
Decrease the key length
A steel containing 0.8% carbon is known as
Eutectoid steel
Hypereutectoid steel
Hypo-eutectoid steel
None of these
If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation
124 d
138 d
151 d
168 d
Transverse fillet welded joints are designed for
Tensile strength
Compressive strength
Shear strength
Bending strength
A crankshaft is a __________ shaft.
Transmission
Machine
Machine frame
None of these
The taper on key is given on
Bottom side only
Top side only
On both sides
Any side
For general industrial machinery, the ratio of the length of journal to its diameter is taken as
0.5 to 1
1 to 2
3 to 5
5 to 10