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
Correct Answer :
D. All of the above
Related Questions
The resultant of the following three couples 20 kg force, 0.5 m arm, +ve sense 30 kg force, 1 m arm, -ve sense 40 kg force, 0.25 m arm, +ve sense having arm of 0.5 m will be
20 kg, -ve sense
20 kg, + ve sense
10 kg, + ve sense
10 kg, -ve sense
The velocity ratio of a first system of pulleys with 4 pulleys is
4
8
16
20
The static friction
Bears a constant ratio to the normal reaction between the two surfaces
Is independent of the area of contact, between the two surfaces
Always acts in a direction, opposite to that in which the body tends to move
All of the above
One joule means that
Work is done by a force of 1 N when it displaces a body through 1 m
Work is done by a force of 1 kg when it displaces a body through 1 m
Work is done by a force of 1 dyne when it displaces a body through 1 cm
Work is done by a force of 1 g when it displaces a body through 1 cm
A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
25
50
100
250
Mass moment of inertia of a thin rod about its one end is __________ the mass moment of inertia of the same rod about its midpoint
Same as
Twice
Thrice
Four times
Non-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 moment of inertia of a square of side a about its diagonal is
a2/8
a3/12
a4/12
a4/16
Pick up wrong statement about friction force for dry surfaces. Friction force is
Proportional to normal load between the surfaces
Dependent on the materials of contact surface
Proportional to velocity of sliding
Independent of the area of contact surfaces
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
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
One kg force is equal to
7.8 N
8.9 N
9.8 N
12 N
Pick up the incorrect statement from the following:
The C.G. of a circle is at its centre
The C.G. of a triangle is at the intersection of its medians
The C.G. of a rectangle is at the intersection of its diagonals
The C.G. of a semicircle is at a distance of r/2 from the centre
A pendulum which executes one beat per second is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
Coefficient 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 friction force acting when the body is just about to move
The friction force acting when the body is in motion
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)
A block of mass m1, placed on an inclined smooth plane is connected by a light string passing over a smooth pulley to mass m2, which moves vertically downwards as shown in the below figure. The tension in the string is 
m1/m2
m1. g. sin α
m1.m2/m1 + m2
m1. m2.g (1 + sin α)/(m1 + m2)
The forces, which meet at one point, but their lines of action do not lie in a plane, are called
Coplanar non-concurrent forces
Non-coplanar concurrent forces
Non-coplanar non-concurrent forces
Intersecting forces
The unit of work in S.I. units is
Newton
erg
kg-m
joule
If rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella
More inclined when moving
Less inclined when moving
More inclined when standing
Less inclined when standing
The maximum frictional force, which comes into play, when a body just begins to slide over the surface of the other body, is known as
Static friction
Dynamic friction
Limiting friction
Coefficient of friction
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 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
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 width (b), is
db³/12
bd³/12
db³/36
bd³/36
The C.G. of a right circular solid cone of height h lies at the following distance from the base
h/2
J/3
h/6
h/4
When trying to turn a key into a lock, following is applied
Coplanar force
Non-coplanar forces
Moment
Couple
The velocity ratio for the first system of pulleys is (where n is the number of pulleys.)
n
n²
2n
2n - 1
If a body is acted upon by a number of coplanar non-concurrent forces, it may
Rotate about itself without moving
Move in any one direction rotating about itself
Be completely at rest
All of these
Two like parallel forces are acting at a distance of 24 mm apart and their resultant is 20 N. It the line of action of the resultant is 6 mm from any given force, the two forces are
15 N and 5 N
20 N and 5 N
15 N and 15 N
None of these
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