If tension in the cable supporting a lift moving downwards is half the tension when it is moving upwards, the acceleration of the lift is
g/2
g/3
g/4
None of these
Correct Answer :
D. None of these
Related Questions
The law of motion involved in the recoil of gun is
Newton's first law of motion
Newton's second law of motion
Newton's third law of motion
None of these
The angle of inclination of the plane at which the body begins to move down the plane, is called
Angle of friction
Angle of repose
Angle of projection
None of these
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
The velocity ratio of a differential wheel and axle with D as the diameter of effort wheel and d1 and d2 as the diameters of larger and smaller axles respectively, is
D/(d₁ + d₂)
D/(d₁ - d₂)
2D/(d₁ + d₂)
2D/(d₁ - d₂)
The force required to move the body up the plane will be minimum if it makes an angle with the inclined plane __________ the angle of friction.
Equal to
Less than
Greater than
None of these
If a rigid body is in equilibrium under the action of three forces, then
These forces are equal
The lines of action of these forces meet in a point
The lines of action of these forces are parallel
Both (B) and (C) above
Which of the following is an equation of linear motion? (where, u and v = Initial and final velocity of the body, a = Acceleration of the body, and s = Displacement of the body in time t seconds.)
v = u + a.t
s = u.t + ½ a.t2
v2 = u2 + 2a.s
All of these
Two blocks A and B of masses 150 kg and 50 kg respectively are connected by means of a string as shown in the below figure. The tension in all the three strings __________ be same. 
Will
Will not
Either A or B
None of these
The minimum force required to slide a body of weight W on a rough horizontal plane is
W sinθ
W cosθ
W tanθ
None of these
Moment of inertia of a triangular section of base (b) and height (h) about an axis through its base, is
bh3/4
bh3/8
bh3/12
bh3/36
A block of mass 20 kg lying on a rough horizontal plane is connected by a light string passing over a smooth pulley to another mass 5 kg, which can move freely in the Vertical direction, as shown in the below figure. The tension in the string will __________ with the increase in coefficient of friction. 
Increase
Decrease
Not be effected
None of these
The periodic time of one oscillation for a simple pendulum is (where l = Length of the pendulum.)
(1/2π). √(l/g)
(1/2π). √(g/l)
2π. √(l/g)
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
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
The centre of gravity of a quadrant of a circle lies along its central radius (r) at a distance of
0.5r
0.6 r
0.7 r
0.8 r
The moment of the force P about O as shown in the below figure is 
P × OA
P × OB
P × OC
P × AC
The unit of force in S.I. system of units is
Dyne
Kilogram
Newton
Watt
The horizontal range of a projectile (R) is given by
R = u² cos2α/g
R = u² sin2α/g
R = u² cosα/g
R = u² sinα/g
One joule is equal to
0.1 N-m
1 N-m
10 N-m
100 N-m
The maximum mechanical advantage of a lifting machine is
1 + m
1 - m
1 / m
m
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
The term 'Centroid' is
The same as centre of gravity
The point of suspension
The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
None of the above
When a body of mass m attains a velocity v from rest in time t, then the kinetic energy of translation is
mv2
mgv2
0.5 mv2
0.5 mgv2
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
In determining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than
Two members with unknown forces of the frame
Three members with unknown forces of the frame
Four members with unknown forces of the frame
Three members with known forces of the frame
The range of projectile will be maximum for a given velocity of projectile, when the angle of projection (α) is
β/2
30° + β/2
45° + β/2
60° + β/2
The ratio of static friction to dynamic friction is always
Equal to one
Less than one
Greater than one
None of these
The centre of percussion is below the centre of gravity of the body and is at a distance equal to
h/kG
h2/kG
kG2/h
h × kG
When the lift is moving upwards with some acceleration, the pressure exerted by a man is __________ to its acceleration.
Directly proportional
Inversely proportional
Cube root
None of these
Moment of inertia of a rectangular section having width (b) and depth (d) about an axis passing through its C.G. and parallel to the depth (d), is
db3/12
bd³/12
db³/36
bd³/36