A force while acting on a body may
Change its motion
Balance the forces, already acting on it
Give rise to the internal stresses in it
All of these
Correct Answer :
D. All of these
Related Questions
Angle of friction is the
Angle between normal reaction and the resultant of normal reaction and the limiting friction
Ratio of limiting friction and normal reaction
The ratio of minimum friction force to the friction force acting when the body is just about to move
The ratio of minimum friction force to friction force acting when the body is in motion
The periodic time (T) is given by (where, ω = Angular velocity of particle in rad/s.)
ω/2π
2π/ω
2π × ω
π/ω
If the number of pulleys in a system is equal to its velocity ratio, then it is a __________ system of pulleys
First
Second
Third
None of these
The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by
P + Q
P - Q
P / Q
Q / P
The linear acceleration (a) of a body rotating along a circular path of radius (r) with an angular acceleration of α rad/s2, is
a = α/ r
a = α.r
a = r / α
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
For a self locking machine, the efficiency must be
Equal to 50 %
Less than 50 %
Greater than 50 %
100 %
Moment of inertia is the
Second moment of force
Second moment of area
Second moment of mass
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 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
Coulomb friction is the friction between
Bodies having relative motion
Two dry surfaces
Two lubricated surfaces
Solids and liquids
Static friction is always __________ dynamic friction.
Equal to
Less than
Greater than
None of these
Moment of inertia of a hollow circular section, as shown in the below figure about X-axis, is 
π/16 (D² - d²)
π/16 (D³ - d³)
π/32 (D⁴ - d⁴)
π/64 (D⁴ - d⁴)
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
An ideal machine is one whose efficiency is
Between 60 and 70 %
Between 70 and 80 %
Between 80 and 90 %
100 %
When trying to turn a key into a lock, following is applied
Coplanar force
Non-coplanar forces
Moment
Couple
Forces are called concurrent when their lines of action meet in
One point
Two points
Plane
Perpendicular planes
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
The unit of moment of inertia of an area is
kg-m2
kg-m-s2
kg/m2
m4
The moment of inertia of a solid cone of mass m and base radius r about its vertical axis is
3mr2/5
3mr2/10
2mr2/5
4mr2/5
The resolved part of the resultant of two forces inclined at an angle θ in a given direction is equal to
The algebraic sum of the resolved parts of the forces in the given direction
The sum of the resolved parts of the forces in the given direction
The difference of the forces multiplied by the cosine of θ
The sum of the forces multiplied by the sine of θ
The maximum efficiency of a lifting machine is
1/m
V.R./m
m/V.R.
1/(m × V.R.)
Which of the following statement is incorrect?
A force acting in the opposite direction to the motion of the body is called force of friction
The ratio of the limiting friction to the normal reaction is called coefficient of friction
A machine whose efficiency is 100% is known as an ideal machine
The velocity ratio of a machine is the ratio of load lifted to the effort applied
If u1 and u2 are the velocities of two moving bodies in the same direction before impact and v1 and v2 are their velocities after impact, then coefficient of restitution is given by
(v1 - v2)/(u1 - u2)
(v₂ - v₁)/(u1 - u2)
(u1 - u2)/(v1 - v2)
(u₂ + u₁)/(v₂ + v₁)
Which of the following statement is correct?
The algebraic sum of the forces, constituting the couple is zero
The algebraic sum of the forces, constituting the couple, about any point is the same
A couple cannot be balanced by a single force but can be balanced only by a couple of opposite sense
All of the above
A machine having an efficiency greater than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
A ladder is resting on a rough ground and leaning against a smooth vertical wall. The force of friction will act
Downward at its upper end
Upward at its upper end
Zero at its upper end
Perpendicular to the wall at its upper end
If the masses of both the bodies, as shown in the below figure, are doubled, then the acceleration in the string will be 
Same
Half
Double
None of these
Two bodies of masses m1 and m2 are hung from the ends of a rope, passing over a frictionless pulley as shown in the figure below. The acceleration of the string will be 
g (m1 - m2)/(m1 + m2)
2g (m1 - m2)/(m1 + m2)
g (m1 + m2)/(m1 - m2)
2g (m1 + m2)/(m1 - m2)
The rate of doing work is known as
Potential energy
Kinetic energy
Power
None of these