In a screw jack, the effort required to lower the load is __________ the effort required to raise the same load.
Less than
Equal to
More than
None of these
Correct Answer :
A. Less than
Related Questions
D' Alembert's principle is used for
Reducing the problem of kinetics to equivalent statics problem
Determining stresses in the truss
Stability of floating bodies
Designing safe structures
A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span
2.5 cm
3.0 cm
4.0 cm
5.0 cm
In a framed structure, as shown in the below figure, the force in the member AB is __________ the force in member AC. 
Half
Equal to
Double
None of these
The velocity ratio for the third system of pulleys is
n
n²
2n
2n - 1
The forces which meet at one point, but their lines of action __________ on the same plane, are Known as non-coplanar concurrent forces.
Lie
Do not lie
Either A or B
None of these
The total energy possessed by a system of moving bodies
Is constant at every instant
Varies from point to point
Is maximum in the start and minimum at the end
Is minimum in the start and maximum at the end
If the masses of both the bodies, as shown in the below figure, are reduced to 50 percent, then tension in the string will be 
Same
Half
Double
None of these
The moment of inertia of a square of side a about its diagonal is
a2/8
a3/12
a4/12
a4/16
Coulomb friction is the friction between
Bodies having relative motion
Two dry surfaces
Two lubricated surfaces
Solids and liquids
During elastic impact, the relative velocity of the two bodies after impact is __________ the relative velocity of the two bodies before impact.
Equal to
Equal and opposite to
Less than
Greater than
Two forces are acting at an angle of 120°. The bigger force is 40 N and the resultant is perpendicular to the smaller one. The smaller force is
20 N
40 N
120 N
None of these
Varingon's theorem of moments states that if a number of coplanar forces acting on a particle are in equilibrium, then
Their algebraic sum is zero
Their lines of action are at equal distances
The algebraic sum of their moments about any point in their plane is zero
The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.
In the lever of third order, load W, effort P and fulcrum F are oriented as follows
W between P and F
F between W and P
P between W and F
W, P and F all on one side
A force acting on a body may
Change its motion
Balance the other forces acting on it
Retard its motion
All of the above
The velocity ratio of a first system of pulleys with 4 pulleys is
4
8
16
20
Which of the following are vector quantities?
Angular displacement
Angular velocity
Angular acceleration
All of these
In ideal machines
Mechanical advantage is greater than velocity ratio
Mechanical advantage is equal to velocity ratio
Mechanical advantage is less than velocity ratio
Mechanical advantage is unity
Moment of inertia of a hollow rectangular section as shown in the below figure about X-X axis, is 
(BD³/12) - (bd³/12)
(DB³/12) - (db³/12)
(BD³/36) - (bd³/36)
(DB³/36) - (db³/36)
The coefficient of friction depends upon
Nature of surfaces
Area of contact
Shape of the surfaces
All of the above
If a number of coplanar forces acting at a point be in equilibrium, the sum of clockwise moments must be __________ the sum of anticlockwise moments, about any point.
Equal to
Less than
Greater than
None of these
The range of projectile (R) on an upward inclined plane is
g. cos² β/2u². sin (α + β). cos α
2u². sin (α + β). cos α/g. cos² β
g. cos² β/2u². sin (α - β). cos α
2u². sin (α - β). cos α/g. cos² β
The bodies which rebound after impact are called
Inelastic bodies
Elastic bodies
Neither elastic nor inelastic bodies
None of these
The possible loading in various members of framed structures are
Compression or tension
Buckling or shear
Shear or tension
All of the above
A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Circular arc
Parabola
Hyperbola
Elliptical
One joule is equal to
0.1 N-m
1 N-m
10 N-m
100 N-m
The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction in which the force acts. This statement is known as
Newton's first law of motion
Newton's second law of motion
Newton's third law of motion
None of these
Coplanar concurrent forces are those forces which
Meet at one point, but their lines of action do not lie on the same plane
Do not meet at one point and their lines of action do not lie on the same plane
Meet at one point and their lines of action also lie on the same plane
Do not meet at one point, but their lines of action lie on the same plane
The length of a second's pendulum is
94.9 cm
99.4 cm
100 cm
101 cm
A ladder is resting on a smooth ground and leaning against a rough vertical wall. The force of friction will act
Towards the wall at its upper end
Away from the wall at its upper end
Downward at its upper end
Upward at its upper end
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p