A machine part subjected to __________ is called a strut.
An axial compressive force
A tangential force
An axial tensile force
Any one of these
Correct Answer :
A. An axial compressive force
Related Questions
In the levers of third type, the mechanical advantage is __________ one.
Less than
Equal to
More than
None of these
Which of the following statement is wrong?
The V-belt may be operated in either direction with tight side of the belt at the top or bottom
The V-belt drive is used with large centre distance
The power transmitted by V-belts is less than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts
The ratio of driving tensions in V-belt drive is more than flat belt drives
When compared to the rod of the same diameter and material, a wire rope
Is less flexible
Has a much smaller load carrying capacity
Does not provide much warning before failure
Provides much greater time for remedial action before failure
A sliding bearing in which although lubricant is present, the working surfaces __________ contact each other at least part of the time, is called boundary lubricated bearing.
Partially
Fully
Either A or B
None of these
In a band and block brake, the ratio of tensions on the tight and slack sides of band is given by (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)
T₁/T₂ = μθ × n
T₁/T₂ = (μθ)n
T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n
T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n
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
Resilience of a material is important, when it is subjected to
Combined loading
Fatigue
Thermal stresses
Shock loading
In helical gears, the distance parallel to the axis, between similar faces of adjacent teeth, is called
Normal pitch
Axial pitch
Diametral pitch
Module
Basic shaft is one
Whose upper deviation is zero
Whose lower deviation is zero
Whose lower as well as upper deviations are zero
Does not exist
In radial cams, the follower moves
In a direction parallel to the cam axis
In a direction perpendicular to the cam axis
In any direction irrespective of cam axis
Along the cam axis
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
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
Guest's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
When the connected members are very yielding (soft gasket) as compared to the bolt, then the resultant load on the bolt will be equal to the
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
In static loading, stress concentration is more serious in
Brittle materials
Ductile materials
Brittle as well as ductile materials
Elastic materials
Split nut is a locking device in which
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 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 pin splitted and bent in reverse direction at the other end
The flank of the tooth is the
Surface of the top of the tooth
Surface of the tooth above the pitch surface
Width of the tooth measured along the pitch circle
Surface of the tooth below the pitch surface
In worm gears, the angle between the tangent to the pitch helix and an element of the cylinder, is known as
Helix angle
Pressure angle
Pitch lead angle
None of these
When bevel gears having equal teeth and equal pitch angles connect two shafts whose axes intersect at right angle, then they are known as
Angular bevel gears
Crown bevel gears
Internal bevel gears
Mitre gears
Antifriction bearings are
Sleeve bearings
Hydrodynamic bearings
Thin lubricated bearings
None of the above
In a partial journal bearing, the angle of contact of the bearing with the journal is
120°
180°
270°
360°
When the belt is transmitting maximum power, the belt speed should be
√(Pmax / 2m)
√(Pmax / 3m)
√(Pmax / m)
√(3m /Pmax) Where m = mass of belt per metre (kg/m) Pmax = maximum permissible tension in belt (N)
When the fulcrum is in between the load and effort, the lever is said to be of
First type
Second type
Third type
Any one of these
In a hydrodynamic lubricated bearing
There is a thick film of lubricant between the journal and the bearing
There is a thin film of lubricant between the journal and the bearing
The lubricant is forced between the journal and the bearing, by external pressure
There is no lubricant between the journal and the bearing
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
Wahl's stress factor __________ very rapidly as the spring index decreases.
Increases
Decreases
Remain same
None of these
Residual stress in materials
Acts when external load is applied
Becomes zero when external load is removed
Is independent of external loads
Is always harmful
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
When a belt drive is transmitting maximum power,
Effective tension is equal to centrifugal tension
Effective tension is half of centrifugal tension
Driving tension on slack side is equal to centrifugal tension
Driving tension on tight side is twice the centrifugal tension
In standard taper roller bearings, the angle of taper of outer raceway is
5°
8°
15°
25°