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
Correct Answer :
D. Both A and B is correct
Related Questions
In the calculation of induced shear stress in helical springs, the Wahl's stress factor is used to take care of
Combined effect of transverse shear stress and bending stress in the wire
Combined effect of bending stress and curvature of the wire
Combined effect of transverse shear stress and curvature of wire
Combined effect of torsional shear stress and transverse shear stress in the wire
Which is positive drive?
Flat belt drive
V-belt drive
Crossed belt drive
Timing belt
The distribution of the forces along the length of key fitted in a shaft
Varies linearly
Is uniform throughout
Varies exponentially, being more near the torque-input end
Varies exponentially, being less near the torque-input end
The building up of worn and undersized parts, subjected to repeated loads by electroplating is
Best method
Extremely hazardous
Has no effect as regards fatigue strength
Cheapest method
Crowning on pulley helps
In decreasing the slip of the belt
In increasing the slip of the belt
To keep the belt in centre on a pulley while it is in motion
To increase pulley life
In an oil lubricated journal bearing, the coefficient of friction between the journal and the bearing
Remains constant at all speeds
Is minimum at zero speed and increases monotonically with increase in speed
Is maximum at zero speed and decreases monotonically with increase in speed
Becomes minimum at an optimum speed and then increases with further increase in speed
The bearings of heavy series have capacity ________ over the medium series.
20 to 30%
10 to 20%
30 to 40%
40 to 50%
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
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above
A machine part subjected to __________ is called a strut.
An axial compressive force
A tangential force
An axial tensile force
Any one 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
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
Pick up wrong statement. Fatigue strength can be increased by
Cold working
Shot peening
Grinding and lapping surface
Hot working
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
The ratio of circumferential stress to longitudinal stress in a thin cylinder subjected to an internal pressure is
½
1
2
4
Deep groove ball bearings are used for
Heavy thrust load only
Small angular displacement of shafts
Radial load at high speed
Combined thrust and radial loads at high speed
Yield point in fatigue loading as compared to static loading is
Same
Higher
Lower
Depends on other factors
For a square key made of mild steel, the shear and crushing strength are related as
Shear strength is equal to crushing strength
Shear strength is greater than crushing strength
Shear strength is less than crushing strength
None of the above
The ratio of pitch circle diameter in millimetres to the number of teeth, is called
Circular pitch
Diametral pitch
Module
None of these
Aircraft body is usually fabricated by
Welding
Pre-casting
Riveting
Casting
When a closely coiled helical spring is subjected to a couple about its axis, the stress induced in the wire material of the spring is
Bending stress only
A combination of torsional shear stress and bending
Direct shear stress only
A combination of bending stress and direct shear stress
If threads on a bolt are left hand, threads on nut will be
Right hand with same pitch
Left hand with same pitch
Could be left or right hand
Right hand with fine pitch
Taper on the cotter and slot is provided
On both the sides
On one side only
On none of the sides
May be provided anywhere
For maximum power, the velocity of the belt will be
√(T/m)
√(T/2m)
√(T/3m)
None of these
The piston rod of a steam engine is usually connected to the crosshead by means of
Bolted joint
Knuckle joint
Cotter joint
Universal joint
The maximum stress due to stress concentration in a bar having circular transverse hole, as compared to its static stress without hole will be
Same in both cases
2 times more
3 times more
4 times more
In worm, gears, pitch lead angle is
Half the angle between two inclined faces in axial plane
The angle between the tangent to the pitch helix and the plane of rotation
The angle between the tangent to the pitch helix and an element of the cylinder
None of the above
A sliding bearing which can support steady loads without any relative motion between the journal and the bearing, is called
Hydrostatic lubricated bearing
Hydrodynamic lubricated bearing
Boundary lubricated bearing
Zero film bearing
In order to ensure self locking in a screw jack, it is essential that helix angle is __________ friction angle.
Larger than
Smaller than
Equal to
None of these
The permissible stress for carbon steel under static loading is generally taken as
2000-3000 kg/m²
3000-4000 kg/cm²
4000-4500 kg/cm²
7500-10,000 kg/cm²