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
Correct Answer :
C. Axially upwards or downwards
Related Questions
The strength of a riveted joint is equal to
Tearing strength of plate (Pt)
Shearing strength of rivet (Ps)
Crushing strength of rivet (Pc)
Least value of Pt Ps and Pc
In a marine flange coupling, the thickness of flange is taken as
d/2
d/3
3d/4
d/4
A connecting rod is designed as a
Long column
Short column
Strut
All of these
A connecting rod subjected to an axial load may buckle with
X-axis as neutral axis
Y-axis as neutral axis
X-axis or Y-axis as neutral axis
Z-axis
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 fatigue stress concentration factor is defined as
The ratio of endurance limit with stress concentration to the endurance limit without stress concentration
The ratio of endurance limit without stress concentration to the endurance limit with stress concentration
The product of the endurance limits with and without stress concentration
All of the above
In case of thick cylinders, the tangential stress across the thickness of cylinder is
Maximum at the outer surface and minimum at the inner surface
Maximum at the inner surface and minimum at the outer surface
Maximum at the inner surface and zero at the outer surface
Maximum at the outer surface and zero at the inner surface
Two shafts A and B are made of the same material. The diameter of shaft A is twice as that of shaft B. The power transmitted by the shaft A will be __________ of shaft B.
Twice
Four times
Eight times
Sixteen times
If the centre distance of the mating gears having involute teeth is varied within limits, the velocity ratio.
Increases
Decreases
Remains unchanged
None of these
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
A steel containing 0.8% carbon is known as
Eutectoid steel
Hypereutectoid steel
Hypo-eutectoid steel
None of these
The valve rod in a steam engine is connected to an eccentric rod by
Cotter joint
Bolted joint
Knuckle joint
Universal coupling
A bolt is designed on the basis of __________ with a large factor of safety.
Direct tensile stress
Direct compressive stress
Direct bending stress
Direct shear stress
In order to have a connecting rod equally strong in buckling about X-axis and Y-axis, the moment of inertia about X-axis should be __________ the moment of inertia about Y-axis.
Equal to
Twice
Three times
Four times
The notch angle of the Izod impact test specimen is
10°
20°
30°
45°
In designing thick cylinders, the equation used is
Lame's equation
Birnie's equation
Clavarinos' equation
All of these
Guest's theory of failure is applicable for following type of materials
Brittle
Ductile
Elastic
Plastic
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
According to Unwin's formula, the relation between the diameter of rivet hole (d) and the thickness of plate (t) is given by (where d and t are in mm)
d = t
d = 1.6 t
d = 2t
d = 6t
A single strap butt joint is always in __________ shear.
Single
Double
Triple share
None of these
The cold working of metals is carried out __________ the recrystallisation temperature.
Above
Below
At
None of these
If P1 and P2 are the tight and slack side tensions in the belt, then the initial tension Pi (neglecting centrifugal tension) will be equal to
P1 - P2
P1 + P2
2 × (P1 + P2)
[2 × (P1 + P2)] + Pc Where Pc is centrifugal tension
The washer is generally specified by its
Outer diameter
Hole diameter
Thickness
Mean diameter
Which of the following statement is correct, for two shafts connected in parallel?
Torque in each shaft is the same
Shear stress in each shaft is the same
Angle of twist of each shaft is the same
Torsional stiffness of each shaft is the same
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
The shear stress at a point in a shaft subjected to a torque is
Directly proportional to the polar moment of inertia and to the distance of the point from the axis
Directly proportional to the applied torque and inversely proportional to the polar moment of inertia
Directly proportional to the applied torque and the polar moment of inertia
Inversely proportional to the applied torque and the polar moment of inertia
Which of the following material has the maximum ductility?
Copper
Mild steel
Aluminium
Zinc
Which of the following statement is wrong for a connecting rod?
The connecting rod will be equally strong in buckling about X-axis and Y-axis, if Ixx = 4 Iyy
If Ixx > 4 Iyy, the buckling will occur about Y-axis
If Ixx < 4 Iyy, the buckling will occur about X-axis
The most suitable section for the connecting rod is T-section
A localised compressive stress at the area of contact between two members is known as
Bending stress
Shear stress
Tensile stress
Bearing stress
The velocity factor for ordinary cut gears operating at velocities upto 12.5 m/s is equal to
0.75/ (0.75 + √v)
3/ (3 + v)
4.5/ (4.5 + v)
6/ (6 + v)