The maximum efficiency of a square threaded screw is
(1 - sinφ)/ (1 + sinφ)
(1 + sinφ)/ (1 - sinφ)
(1 - sinφ)/ (1 + cosφ)
(1 + cosφ)/ (1 - sinφ)
Correct Answer :
A. (1 - sinφ)/ (1 + sinφ)
Related Questions
The objective of caulking in a riveted joint is to make the joint
Free from corrosion
Stronger in tension
Free from stress
Leak-proof
Spring stiffness is
Ratio of coil diameter to wire diameter
Load required to produce unit deflection
Its capability of storing energy
Its ability to absorb shocks
Turn buckle has
Right hand threads on bout ends
Left hand threads on both ends
Left hand threads on one end and right hand threads on other end
No threads
Two shafts will have equal strength, if
Diameter of both the shafts is same
Angle of twist of both the shafts is same
Material of both the shafts is same
Twisting moment of both the shafts is same
According to Indian standards, total numbers of tolerance grades are
8
12
18
20
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)
Which of the following coupling is used to connect two shafts which have both lateral and angular misalignment?
Bushed pin type coupling
Universal coupling
Oldham coupling
All of these
The bending stress in a curved beam is
Zero at the centroidal axis
Zero at the point other than centroidal axis
Maximum at the neutral axis
None of these
A compound cylinder with inner radius 50 mm and outer radius 70 mm is made by shrinking one cylinder on to the other cylinder, the junction radius is 60 mm and the junction pressure is 1.1 N/mm². The maximum hoop stress developed in the inner cylinder is
3.6 N/mm² compression
3.6 N/mm² tension
7.2 N/mm² compression
7.2 N/mm² tension
Which is correct statement?
A member made of steel will generally be more rigid than a member of equal load carrying ability made of cast iron
A member made of cast iron will generally be more rigid than a member of equal load carrying ability made of steel
Both will be equally rigid
Which one is rigid will depend on several other factors
The permissible stress in the fillet weld is 100 N/mm². The fillet weld has equal leg lengths of 15 mm each. The allowable shearing load on the weldment per cm length of the weld is
7.5 kN
10.6 kN
15 kN
22.5 kN
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
Taper usually provided on cotter is
1 in 5
1 in 10
1 in 24
1 in 40
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
According to Indian standards, the diameter of rivet hole is made larger than the basic size of rivet by
0.5 mm upto rivet diameter of 24 mm
1 mm for rivet diameter from 27 mm to 36 mm
2 mm for rivet diameter from 39 mm to 48 mm
All of the above
For a shoe brake, the equivalent coefficient of friction is equal to (where μ = Actual coefficient of friction, and θ = Semi-block angle)
2μ sinθ/(θ + sinθ)
μ sinθ/(2θ + sin 2θ)
4μ sinθ/(θ + sinθ)
4μ sinθ/(2θ + sin 2θ)
The dedendum circle diameter is equal to (where φ = Pressure angle)
Pitch circle diameter × cosφ
Addendum circle diameter × cosφ
Clearance circle diameter × cosφ
Pitch circle diameter × sinφ
A double strap butt joint (with equal straps) is
Always in single shear
Always in double shear
Either in single shear or double shear
Any one of these
A column is known as a long column if the slenderness ratio is
40
50
70
100
In a multiple V-belt drive, when a single belt is damaged, it is preferable to change the complete set in order to
Reduce vibration
Reduce slip
Ensure uniform loading
Ensure proper alignment
A locking device in which the bottom cylindrical portion is recessed to receive the tip of the locking set screw, is called
Ring nut
Castle nut
Sawn nut
Jam nut
A connecting rod should be
Strong in buckling about X-axis
Strong in buckling about Y-axis
Equally strong in buckling about X-axis and Y-axis
Any one of the above
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
A bolt of uniform strength can be developed by
Keeping the core diameter of threads equal to the diameter of unthreaded portion of the bolt
Keeping the core diameter smaller than the diameter of the unthreaded portion
Keeping the nominal diameter of threads equal to the diameter of unthreaded portion of the bolt
None of the above
During hot working of metals,
Porosity of the metal is largely eliminated
Grain structure of the metal is refined
Mechanical properties are improved due of refinement of grains
All of the above
Stress concentration is caused due to
Variation in properties of material from point to point in a member
Pitting at points or areas at which loads on a member are applied
Abrupt change of section
All of the above
When a material is subjected to fatigue loading, the ratio of the endurance limit to the ultimate tensile strength is
0.20
0.35
0.50
0.65
In a flat belt drive, if the slip between the driver and belt is 1 %, between the belt and follower is 3% and driver and follower pulley diameters are equal, then velocity ratio of the drive will be
0.96
0.97
0.98
0.99
When a beam of rectangular cross-section of width b and depth d, is subjected to a shear force F, the maximum shear stress induced will be
F/bh
3F/2bh
2F/bh
4F/bh
The property of a material which enables it to be drawn into wires with the application of a tensile force, is called
Plasticity
Elasticity
Ductility
Malleability