If three forces acting in different planes can be represented by a triangle, these will be in
Non-equilibrium
Partial equilibrium
Full equilibrium
Unpredictable
Correct Answer :
A. Non-equilibrium
Related Questions
The unit of energy in S.I. units is
Dyne
Watt
kg-m
Joule
The three forces of 100 N, 200 N and 300 N have their lines of action parallel to each other but act in the opposite directions. These forces are known as
Coplanar concurrent forces
Coplanar non-concurrent forces
Like parallel forces
Unlike parallel forces
The moment of a force
Is the turning effect produced by a force, on the body, on which it acts
Is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force
Is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the moment is taken
All of the above
The force, by which the body is attracted, towards the centre of the earth, is called
Impulsive force
Mass
Weight
Momentum
The centre of gravity of a trapezium with parallel sides a and b lies at a distance of y from the base b, as shown in the below figure. The value of y is 
h [(2a + b)/(a + b)]
(h/2) [(2a + b)/(a + b)]
(h/3) [(2a + b)/(a + b)]
(h/3) [(a + b)/(2a + b)]
The velocity ratio of a single purchase crab winch can be increased by
Increasing the length of the handle
Increasing the radius of the load drum
Increasing the number of teeth of the pinion
All of the above
The principle of transmissibility of forces states that, when a force acts upon a body, its effect is
Same at every point on its line of action
Different at different points on its line of action
Minimum, if it acts at the centre of gravity of the body
Maximum, if it acts at the centre of gravity of the body
The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction.)
α = 45° + φ/2
α = 45° - φ/2
α = 90° + φ
α = 90° - φ
Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one
Ellipse
Hyperbola
Parabola
Circle
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
A screw jack used for lifting the loads is
A reversible machine
A non-reversible machine
An ideal machine
None of these
The rate of change of displacement of a body is called
Velocity
Acceleration
Momentum
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
Concurrent forces are those forces whose lines of action
Lie on the same line
Meet at one point
Meet on the same plane
None of these
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
Centre of gravity of a solid cone lies on the axis at the height
One fourth of the total height above base
One third of the total height above base
One-half of the total height above base
Three eighth of the total height above the base
Dynamic friction as compared to static friction is
Same
More
Less
May be less of more depending on nature of surfaces and velocity
If the body falls freely under gravity, then the gravitational acceleration is taken as
+8.9 m/s2
-8.9 m/s2
+9.8 m/s2
-9.8 m/s2
The velocity of a body on reaching the ground from a height h, is
2.√(gh)
√(gh)
√(2gh)
2g.√h
The moment of inertia of a solid cylinder of mass m, radius r and length l about the longitudinal axis or polar axis is
mr2/2
mr2/4
mr2/6
mr2/8
Which of the following do not have identical dimensions?
Momentum and impulse
Torque and energy
Torque and work
Moment of a force and angular momentum.
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 efficiency of a lifting machine is the ratio of
Output to the input
Work done by the machine to the work done on the machine
Mechanical advantage to the velocity ratio
All of the above
If a number of forces are acting at a point, their resultant is given by
(ΣV)2 + (ΣH)2
√[(ΣV)2 + (ΣH)2]
(ΣV)2 +(ΣH)2 +2(ΣV)(ΣH)
√[(ΣV)2 +(ΣH)2 +2(ΣV)(ΣH)]
According to law of triangle of forces
Three forces acting at a point will be in equilibrium
Three forces acting at a point can be represented by a triangle, each side being proportional to force
If three forces acting upon a particle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium
If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two
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
Moment of inertia of a hollow circular section, as shown in the below figure about an axis perpendicular to the section, is __________ than that about X-X axis. 
Two times
Same
Half
None of these
A machine having an efficiency less than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
Kinetic friction is the
Tangent of angle between normal reaction and the resultant of normal reaction and the limiting friction
Ratio of limiting friction and normal reaction
The friction force acting when the body is just about to move
The friction force acting when the body is in motion
If n = number of members and y = number of joints, then for a perfect frame, n = ?
1/2
2/3
3/2
2/4