The point, through which the whole weight of the body acts, irrespective of its position, is known as
Moment of inertia
Centre of gravity
Centre of percussion
Centre of mass
Correct Answer :
B. Centre of gravity
Related Questions
Efficiency of a screw jack is given by (where α = Helix angle, and φ = Angle of friction.)
tan(α + φ)/tanα
tanα/tan (α + φ)
tan(α - φ)/tanα
None of these
The algebraic sum of moments of the forces forming couple about any point in their plane is
Equal to the moment of the couple
Constant
Both of above are correct
Both of above are wrong
The law of the machine is (where P = Effort applied to lift the load, m = A constant which is equal to the slope of the line, W = Load lifted, and C = Another constant which represents the machine friction.)
P = mW - C
P = m/W + C
P = mW + C
P = C - mW
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
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
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
The motion of a particle round a fixed axis is
Translatory
Rotary
Circular
Translatory as well as rotary
The bodies which rebound after impact are called
Inelastic bodies
Elastic bodies
Neither elastic nor inelastic bodies
None of these
The velocity of a particle moving with simple harmonic motion is __________ at the mean position.
Zero
Minimum
Maximum
None of these
On the ladder resting on the ground and leaning against a smooth vertical wall, the force of friction will be
Downwards at its upper end
Upwards at its upper end
Perpendicular to the wall at its upper end
Zero at its upper end
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
A body of weight W is required to move up on rough inclined plane whose angle of inclination with the horizontal is α. The effort applied parallel to the plane is given by (where μ = tanφ = Coefficient of friction between the plane and the body.)
P = W tanα
P = W tan (α + φ)
P = W (sinα + μcosα)
P = W (cosα + μsinα)
When a rigid body is suspended vertically, and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
Simple pendulum
Compound pendulum
Torsional pendulum
Second's pendulum
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
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 centre of gravity of a semi-circle lies at a distance of __________ from its base measured along the vertical radius.
3r/ 8
4r/ 3π
8r/3
3r/4π
The units of moment of inertia of mass are
kg-m²
m²/kg.
kg/m²
kg/m
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p
Coplanar non-concurrent forces are those forces which __________ at one point, but their lines of action lie on the same plane.
Meet
Do not meet
Either A or B
None of these
Effect of a force on a body depends upon
Magnitude
Direction
Position or line of action
All of the above
The total momentum of a system of masses (i. e. moving bodies) in any one direction remains constant, unless acted upon by an external force in that direction. This statement is called
Newton's first law of motion
Newton's second law of motion
Principle of conservation of energy
Principle of conservation of momentum
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 unit of force in S.I. units is
kilogram
Newton
Watt
Dyne
A heavy string attached at two ends at same horizontal level and when central dip is very small approaches the following curve
Circular arc
Parabola
Hyperbola
Elliptical
Dynamic friction as compared to static friction is
Same
More
Less
May be less of more depending on nature of surfaces and velocity
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
The forces, whose lines of action are parallel to each other and act in the same directions, are known as
Coplanar concurrent forces
Coplanar non-concurrent forces
Like parallel forces
Unlike parallel forces
In actual machines, mechanical advantage is __________ velocity ratio.
Equal to
Less than
Greater than
None of these
In a framed structure, as shown in the below figure, the force in the member AB is __________ the force in member AC. 
Half
Equal to
Double
None of these
The angular velocity (in rad/s) of a body rotating at N revolutions per minute is
πN/60
πN/180
2πN/60
2πN/180