The load cup of a screw jack is made separate from the head of the spindle to
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
Correct Answer :
A. Prevent the rotation of load being lifted
Related Questions
Wire ropes as compared to cotton ropes
Are lighter in weight
Offer silent operation
Can withstand shock loads
All of these
Fabric belts are used in industrial applications because
They are cheap
They can work at high temperature
They are unaffected by moisture and humidity
None of the above
In a steam engine, the piston rod is usually connected to the crosshead by means of a
Knuckle joint
Cotter joint
Oldham coupling
Universal joint
In radial bearings, the load acts __________ to the axis of rotation.
Parallel
Perpendicular
Both A and B
None of these
Which of the following statement is correct regarding power screws?
The efficiency of a self locking screw can not be more than 50%
The efficiency of Acme (trapezoidal) thread is less than that of a square thread
If the friction angle is less than the helix angle of the screw, then the efficiency will be more than 50%
(A) and (B) Only
Crushing resistance required to crush the rivet per pitch length is
p.d.σc
p.t.σc
n.d.t.σc
(p - d) t.σc
Machine screws are
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 two parts
Similar to stud
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
A backing ring is used inside the pipe joint when making a
Butt weld
Fillet weld
Sleeve weld
Socket weld
The load cup of a screw jack is made separate from the head of the spindle to
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
The design of pin of a rocker arm of an I.C. engine is based on
Bearing failure
Shearing failure
Bending failure
All of these
The design of shafts made of brittle materials is based on
Guest's theory
Rankine's theory
St Venant's theory
Von Mises theory
A spring is used to
Measure forces
Apply forces
Store energy
All of these
For steel, the ultimate strength in shear as compared to ultimate strength in tension is
1/2
1/3
1/4
2/3
When the shaft rotates in anticlockwise direction at slow speed in a bearing, it will
Have contact at the bottom most of the bearing
Move towards right of the bearing making no metal to metal contact
Move towards right of the bearing making the metal to metal contact
Move towards left of the bearing making metal to metal contact
When a circular beam of diameter d is subjected to a shear force F, the maximum shear stress induced will be
4F/ πd²
6F/ πd²
8F/ πd²
16F/ 3πd²
The material generally used for aircraft components is
Mild steel
High speed steel
Stainless steel
Aluminium
The toughness of a material _________ when it is heated
Does not change
Increases
Decreases
None of the Above
Auto frettage is the method of
Joining thick cylinders
Calculating stresses in thick cylinders
Pre-stressing thick cylinders
Increasing the life of thick cylinders
In nitrated parts, the origins of the fatigue cracks will occur at
Surface
Just below the surface
Within the core
None of the above
In order to have a connecting rod equally strong in buckling about X-axis and Y-axis, the moment of inertia about X-axis should be __________ the moment of inertia about Y-axis.
Equal to
Twice
Three times
Four times
For tight leakage joints, following type of thread is best suited
Metric
Buttress
Square
NPT (national pipe threads)
The cam follower extensively used in aircraft engines is
Knife edge follower
Flat faced follower
Spherical faced follower
Roller follower
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
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
The following type of nut is used with alien bolt
Hexagonal nut
Slotted nut
Castle nut
Any one of the above
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
A column of length l is fixed at both ends. The equivalent length of the column is
l/2
l/√2
l
2 l
When a hole of diameter d is punched in a metal of thickness 't', then the force required to punch a hole is equal to (where τu = Ultimate shear strength of the material of the plate)
d.t.τu
πd.t.τu
π/4 × d².τu
π/4 × d² × t.τu
While designing a screw in a screw jack against buckling failure, the end conditions for the screw are taken as
Both the ends fixed
Both the ends hinged
One end fixed and the other end hinged
One end fixed and the other end free