Same time to reach earth
Times proportional to weight to reach earth
Times inversely proportional to weight to reach earth
None of the above
A. Same time to reach earth
Larger
Smaller
Equal
Larger/smaller depending on diameter of spring coil
A parallel sunk key is a taperless key
A parallel sunk key may be rectangular or square in cross-section
A flat saddle key is a taper key which fits in a key way of the hub and is flat on the shaft
All of the above
Pulley is made the weakest
Key is made the weakest
Key is made the strongest
All the three are designed for equal strength
Increases
Decreases
Remain same
None of these
Bearing failure
Shearing failure
Bending failure
All of these
10 to 20 %
20 to 30 %
30 to 40 %
40 to 50 %
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
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
Decrease the tendency of belt to slip
Increase the power transmission capacity
Increase the wrap angle and belt tension
All the above objectives
Flanged
Threaded
Bell and spigot
Expansion
Same
Coarser
Finer
Very fine
18
16
20
22
Very serious in brittle materials and less serious in ductile materials
Very serious in ductile materials and less serious in brittle materials
Equally serious in both types of materials
Seriousness would depend on other factors
Bolts and nuts
Studs
Headless taper bolts
None of these
1420 d
1680 d
2080 d
2840 d
d + 17 mm
2d + 13 mm
2d + 20 mm
3.5d
1 kN-m
2 kN-m
3 kN-m
4 kN-m
Similar to small size tap bolts except that a greater variety of shapes of heads are available
Slotted for a screw driver and generally used with a nut
Used to prevent relative motion between parts
Provided with detachable caps
It is subjected to a higher cyclic loading than the outer side
It is subjected to a higher stress than the outer side
It is more stretched than the outer side during the manufacturing process
It has a lower curvature than the outer side
Tensile stress
Compressive stress
Shear stress
Bending stress
45 to 60 %
63 to 70 %
70 to 83 %
80 to 90 %
Pan Head
Snap head
Counter sunk head
Conical head
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
T/2
T
2T
4T
3 mm
6 mm
8 mm
12 mm
Diameter of bolt
0.75 × diameter of bolt
1.25 × diameter of bolt
1.5 × diameter of bolt
Mild steel
High speed steel
Stainless steel
Aluminium
Lighter and easier to handle
Greater shock absorption
Smoother inside walls
All of the above
F + P
F P
P
F
The distance from a point on one thread to the corresponding point on the next thread is called pitch
The distance which a screw thread advances axially in one rotation of the nut is called lead
In single start threads, lead is equal to pitch
All of the above