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
C. Shafts are arranged parallel and rotate in the same directions
One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening a screw
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter spitted and bent in reverse direction at other end
Varies linearly
Is uniform throughout
Varies exponentially, being more near the torque-input end
Varies exponentially, being less near the torque-input end
More
Less
Same
More or less depending on quantum of load
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
Cast iron
Wrought iron
Mild steel
Aluminium
Jam nut
Castle nut
Sawn nut
Ring nut
Both sides of the actual size
One side of the actual size
One side of the nominal size
Both sides of the nominal size
Less than
Equal to
More than
None of these
1100 to 1300°C
1300 to 1500°C
500 to 600°C
700 to 900°C
Prevent the rotation of load being lifted
Enhance the load carrying capacity of the jack
Reduce the effort needed for lifting the working load
Reduce the value of frictional torque
Decreasing the cross-section area of bar
Increasing the cross-section area of bar
Remain unaffected with cross-section area
Would depend upon other factors
√2P/s.l
P/2.s.l
P/√2.s.l
2P/s.l
More than 50 %
Less than 50 %
Equal to 50 %
None of these
30°
45°
60°
80°
Equal to
sinα times more than
sinα times less than
cosecα times more than
Friction angle is less than helix angle
Friction angle is more than helix angle
Friction angle is equal to helix angle
Efficiency of screw is 100%
Regain its original shape after deformation when the external forces are removed
Draw into wires by the application of a tensile force
Resist fracture due to high impact loads
Retain deformation produced under load permanently
Young's modulus
Coefficient of elasticity
Elastic limit
Endurance limit
Less than 50 %
More than 50 %
Equal to 50 %
None of these
Basic size is 100 mm
Actual size is 100 mm
Difference between the actual size and basic size is 100 mm
None of the above
Bending stress only
A combination of torsional shear stress and bending
Direct shear stress only
A combination of bending stress and direct shear stress
Prevent the belt from running off the pulley
Increase the power transmission capacity
Increase the belt velocity
Prevent the belt joint from damaging the belt surface
Direction of twist of wires in strands is opposite to the direction of twist of strands
Direction of twist of wires and strands are same
Wires in two adjacent strands are twisted in opposite direction
Wires are not twisted
Low efficiency
High efficiency
High load lifting capacity
High mechanical advantage
10°
20°
30°
45°
Base circle
Pitch circle
Prime circle
Pitch curve
8
6
4
2
(1 - sinφ)/ (1 + sinφ)
(1 + sinφ)/ (1 - sinφ)
(1 - sinφ)/ (1 + cosφ)
(1 + cosφ)/ (1 - sinφ)
Flanged
Threaded
Bell and spigot
Expansion
Centroidal axis
Neutral axis
Inside fibre
Outside fibre