The design calculations for members subject to fluctuating loads with the same factor of safety, yield the most conservative estimates when using
Gerber relation
Soderberg relation
Goodman relation
None of these
Correct Answer :
C. Goodman relation
Related Questions
The draw of cotter need not exceed
3 mm
5 mm
10 mm
20 mm
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 chain drive transmits __________ power as compared to belt drive.
More
Less
Same
None of these
When an open coiled helical compression spring is subjected to an axial load (W), the compression produced in the spring will be (where n = No. of active turns of the spring, and G = Modulus of rigidity for the spring material)
2WD3n/Gd⁴
4WD3n/Gd⁴
8WD3n/Gd⁴
16WD3n/Gd⁴
In a marine flange coupling, the thickness of flange is taken as
d/2
d/3
3d/4
d/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
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
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
For steel, the ultimate strength in shear as compared to ultimate strength in tension is
1/2
1/3
1/4
2/3
The design of shafts made of brittle materials is based on
Guest's theory
Rankine's theory
St Venant's theory
Von Mises theory
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
According to I.B.R., shearing resistance required to shear off the rivet per pitch length (in double shear) is (where n = Number of rivets per pitch length)
(π/4) d² × τ × n
1.875 × (π/4) d² × τ × n
2 × (π/4) d² × τ × n
3 × (π/4) d² × τ × n
Rankine Gordon formula for buckling is valid for
Long column
Short column
Short and long column
Very long column
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
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 V-belt designated as B 4430 LP has
4430 mm as diameter of small pulley
4430 mm as nominal pitch length
4430 mm as diameter of large pulley
4430 mm as centre distance between pulleys
Which of the following cotter joint will be used to connect strap end of a connecting rod?
Spigot and socket cotter joint
Sleeve and cotter joint
Gib and cotter joint
Any one of these
In replacing the V-belts, a complete set of new belts is used instead of replacing a single damaged belt because
Belts are available in sets
Only one belt cannot be fitted with other used belts
The new belt will carry more than its share and result in short life
New and old belts will cause vibrations
A single strap butt joint is always in __________ shear.
Single
Double
Triple share
None of these
For unequal width of butt straps, the thicknesses of butt straps are
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for both the straps on the inside and outside
0.625 t for both the straps on the inside and outside
The deflection of a cantilever beam under load W is 8. If its width is halved, then the deflection under load W will be
2/8
8/2
4/8
8/4
A transmission shaft includes
Over head shaft
Counter shaft
Line shaft
All of these
The maximum bending stress in a curved beam having symmetrical section always occur at the
Centroidal axis
Neutral axis
Inside fibre
Outside fibre
Spring index is
Ratio of coil diameter to wire diameter
Load required to produce unit deflection
Its capability of storing energy
Indication of quality of spring
In designing a sleeve coupling, length of the sleeve is taken as (where d = Diameter of the shaft)
d + 17 mm
2d + 13 mm
2d + 20 mm
3.5d
At low temperatures (say 75°C) the notched bar impact value of steel
Increases markedly
Decreases markedly
Remain same
Depends on heat treatment carried out
If the size of a standard specimen for a fatigue testing machine is increased, the endurance limit for the material will
Have same value as that of standard specimen
Increase
Decrease
None of these
The groove angle of pulleys for V-belt is
340 to 360
420 to 450
More than 400
300 to 320
The power transmitted by the belt drive can be increased by
Increasing the initial tension in the belt
Dressing the belt to increase the coefficient of friction
Increasing wrap angle by using idler pulley
All of the above methods
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