Which of the following statement is correct?
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
Correct Answer :
D. All of the above
Related Questions
The shear stress in a beam varies from zero at the outer fibres to a maximum at the________.
Neutral surface
Upper surface
Lower surface
None of these
Guest's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
An open coiled helical compression spring 'A' of mean diameter 50 mm is subjected to an axial load W. Another spring 'B' of mean diameter 25 mm is similar to spring 'A' in all respects. The deflection of spring 'B' will be __________ as compared to spring 'A'.
One-eighth
One-fourth
One-half
Double
The included angle for the British Association thread is
29°
55°
47.3°
60°
The application of third type levers is found in
Handle of a hand pump
Hand wheel of a punching press
Lever of a loaded safety valve
A pair of tongs
A taper key which fits half in the key way of the hub and half in the key way of shaft, is known as
Angular bevel gears
Mitre gears
Crown Bevel gears
Internal bevel gears
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
The design of the pressure vessel is based on
Longitudinal stress
Hoop stress
Longitudinal and hoop stress
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)
If T₁ and T₂ are the tensions on the tight and slack sides of the belt respectively, and Tc is the centrifugal tension, then initial tension in the belt is equal to
T₁ - T₂ + Tc
T₁ + T₂ + Tc
(T₁ - T₂ + Tc)/2
(T₁ + T₂ + Tc)/2
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 hot short metal is
Brittle when cold
Brittle when hot
Brittle under all conditions
Ductile at high temperature
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 a flange coupling, the flanges are coupled together by means of
Bolts and nuts
Studs
Headless taper bolts
None of these
Aircraft body is usually fabricated by
Welding
Pre-casting
Riveting
Casting
Which of the following is not correct procedure to increase the fatigue limit?
Cold working
Shot peening
Surface decarburisation
Under stressing
When an open coiled helical compression spring is subjected to an axial compressive load, the maximum shear stress induced in the wire is (where D = Mean diameter of the spring coil, d = Diameter of the spring wire, K = Wahl's stress factor, and W = Axial compressive load on the spring)
(WD/ πd3) × K
(2WD/ πd3) × K
(4WD/ πd3) × K
(8WD/ πd3) × K
Whether any core is required in wire ropes
Yes
No
Sometimes
Rarely
In standard taper roller bearings, the angle of taper of outer raceway is
5°
8°
15°
25°
In composite or reverse laid ropes
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
In a full journal bearing, the angle of contact of the bearing with the journal is
120°
180°
270°
360°
When the screw in a mechanical screw jack rotates, the load kept on the top of it moves
Axially upwards
Axially downwards
Axially upwards or downwards
None of these
The suitable material for belt used in flour mill is
Leather
Rubber
Canvas or cotton duck
Balata gum
The square threads are usually found on
Spindles of bench vices
Railway carriage couplings
Feed mechanism of machine tools
Screw cutting lathes
The velocity of sliding ________ the distance of the point of contact from the pitch point.
Is directly proportional to
Is inversely proportional to
Is equal to cos φ multiplied by
Does not depend upon
The number of slots in a 25 mm castle nut is
8
4
2
6
In second type of levers,
Load is in between the fulcrum and effort
Effort is in between the fulcrum and load
Fulcrum is in between the load and effort
None of these
The coefficient of friction between the belt and pulley depends upon the
Material of belt and pulley
Slip of belt
Speed of belt
All of these
In designing a connecting rod, it is considered like __________ for buckling about Y-axis.
Both ends hinged
Both ends fixed
One end fixed and the other end hinged
One end fixed and the other end free
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