In order to completely specify angular displacement by a vector, it must fix
Direction of the axis of rotation
Magnitude of angular displacement
Sense of angular displacement
All of these
Correct Answer :
D. All of these
Related Questions
One watt is equal to
0.1 joule/s
1 joule/s
10 joules/s
100 joules/s
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)]
The moment of inertia of a thin spherical shell of mass m and radius r, about its diameter is
mr2/3
2mr2/3
2mr2/5
3mr2/5
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 unit of force in S.I. system of units is
Dyne
Kilogram
Newton
Watt
The acceleration of a particle moving with simple harmonic motion, at any instant is given by
ω.y
ω2.y
ω2/y
ω3.y
If a given force (or a given system of forces) acting on a body __________ the position of the body, but keeps it in equilibrium, then its effect is to produce internal stress in the body.
Change
Does not change
Changes periodically
None of these
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 weight of a body is due to
Gravitational pull exerted by the earth
Forces experienced by body in atmosphere
Force of attraction experienced by particles
Gravitational force of attraction towards the centre of the earth
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
From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the centre of circular plate
0.5 cm
1.0 cm
1.5 cm
2.5 cm
Forces are called concurrent when their lines of action meet in
One point
Two points
Plane
Perpendicular planes
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 unit of angular velocity is
m/min
rad/s
Revolutions/min
Both (B) and (C)
The moment of inertia of a square of side a about its diagonal is
a2/8
a3/12
a4/12
a4/16
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
Which of the following is a scalar quantity?
Force
Speed
Velocity
Acceleration
A semicircular disc rests on a horizontal surface with its top flat surface horizontal and circular portion touching down. The coefficient of friction between semi circular disc and horizontal surface is μ. This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will
Remain horizontal
Slant up towards direction of pull
Slant down towards direction of pull
None of the above
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
A machine having an efficiency greater than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
One kg force is equal to
7.8 N
8.9 N
9.8 N
12 N
A framed structure is perfect, if the number of members are __________ (2j - 3), where j is the number of joints.
Equal to
Less than
Greater than
None of these
A smooth cylinder lying on a __________ is in neutral equilibrium.
Curved surface
Convex surface
Horizontal surface
None of these
The coefficient of friction depends on
Area of contact
Shape of surfaces
Strength of surfaces
Nature of surface
One end of a helical spring is fixed while the other end carries the load W which moves with simple harmonic motion. The frequency of motion is given by (where δ = Deflection of the spring.)
2π. √(g/δ)
1/2π. √(g/δ)
2π. √(δ/g)
1/2π. √(δ/g)
When trying to turn a key into a lock, following is applied
Coplanar force
Non-coplanar forces
Moment
Couple
If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either
Meet in a point
Be all parallel
At least two of them must meet
All the above are correct
The units of moment of inertia of an area are
kg-m²
m⁴
kg/m²
m³
The velocity of a particle (v) moving with simple harmonic motion, at any instant is given by (where r = Amplitude of motion, and y = Displacement of the particle from mean position.)
ω.√(y² - r²)
ω.√(r² - y²)
ω².√(y² - r²)
ω².√(r² - y²)
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