Moment of inertia of a circular section about its diameter (d) is
πd3/16
πd3/32
πd4/32
πd4/64
Correct Answer :
D. πd4/64
Related Questions
If the resultant of two equal forces has the same magnitude as either of the forces, then the angle between the two forces is
30°
60°
90°
120°
A body moves, from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly
38 m
62.5 m
96 m
124 m
In a single threaded worm and worm wheel, the number of teeth on the worm is 50. The diameter of the effort wheel is 100 mm and that of load drum is 50 mm. The velocity ratio is
50
100
200
400
According to principle of moments
If a system of coplanar forces is in equilibrium, then their algebraic sum is zero
If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
The algebraic sum of the moments of any two forces about any point is equal to moment of the resultant about the same point
Positive and negative couples can be balanced
A smooth cylinder lying on a __________ is in neutral equilibrium.
Curved surface
Convex surface
Horizontal surface
None of these
According to the law of moments, if a number of coplanar forces acting on a particle are in equilibrium, then
Their algebraic sum is zero
Their lines of action are at equal distances
The algebraic sum of their moments about any point in their plane is zero
The algebraic sum of their moments about any point is equal to the moment of their resultant force about the same point.
Which of the following is not the unit of power?
kW (kilowatt)
hp (horse power)
kcal/sec
kcal/kg sec
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
A circular hole of 50 mm diameter is cut out from a circular disc of 100 mm diameter as shown in the below figure. The centre of gravity of the section will lie 
In the shaded area
In the hole
At O
None of these
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
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
The horizontal range of a projectile (R) is given by
R = u² cos2α/g
R = u² sin2α/g
R = u² cosα/g
R = u² sinα/g
In actual machines
Mechanical advantage is greater than velocity ratio
Mechanical advantage is equal to velocity ratio
Mechanical advantage is less than velocity ratio
Mechanical advantage is unity
A force acting on a body may
Change its motion
Balance the other forces acting on it
Retard its motion
All of the above
A block of mass 20 kg lying on a rough horizontal plane is connected by a light string passing over a smooth pulley to another mass 5 kg, which can move freely in the Vertical direction, as shown in the below figure. The tension in the string will __________ with the increase in coefficient of friction. 
Increase
Decrease
Not be effected
None of these
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
Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, is
bh3/4
bh3/8
bh3/12
bh3/36
The range of projectile on a downward inclined plane is ________ the range on upward inclined plane for the same velocity of projection and angle of projection.
Less than
More than
Equal to
None of These
Which of the following is not a scalar quantity?
Mass
Volume
Density
Acceleration
The velocity of a body on reaching the ground from a height h, is
2.√(gh)
√(gh)
√(2gh)
2g.√h
The product of either force of couple with the arm of the couple is called
Resultant couple
Moment of the forces
Resulting couple
Moment of the couple
The bodies which rebound after impact are called
Inelastic bodies
Elastic bodies
Neither elastic nor inelastic bodies
None of these
A framed structure is imperfect, if the numbers of members are __________ (2j - 3).
Equal to
Less than
Greater than
Either (B) or (C)
The angle of inclination of the plane at which the body begins to move down the plane, is called
Angle of friction
Angle of repose
Angle of projection
None of these
Which one of the following statements is not correct?
The tangent of the angle of friction is equal to coefficient of friction
The angle of repose is equal to angle of friction
The tangent of the angle of repose is equal to coefficient of friction
The sine of the angle of repose is equal to coefficient to friction
A projectile is fired at an angle θ to the vertical. Its horizontal range will be maximum when θ is
0°
30°
45°
60°
The velocity ratio of a simple wheel and axle with D and d as the diameters of effort wheel and load axle, is
D + d
D - d
D × d
D / d
The time of flight (t) of a projectile on a horizontal plane is given by
t = 2u. sinα/g
t = 2u. cosα/g
t = 2u. tanα/g
t = 2u/g.sinα
The angular velocity (in rad/s) of a body rotating at N revolutions per minute is
πN/60
πN/180
2πN/60
2πN/180
The total motion possessed by a body, is called
Impulsive force
Mass
Weight
Momentum