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
Correct Answer :
B. 3mr2/10
Related Questions
The unit of angular acceleration is
N-m
m/s
m/s2
rad/s2
The term 'Centroid' is
The same as centre of gravity
The point of suspension
The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
None of the above
A body of mass m moving with a constant velocity v strikes another body of same mass moving with same velocity but in opposite direction. The common velocity of both the bodies after collision is
v
2v
4v
8v
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p
The maximum acceleration of a particle moving with simple harmonic motion is
ω
ωr
ω2r
ω/r
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
The ideal angle of banking provided on the curves on roads depends upon
Weight of the vehicle
(Velocity)2 of the vehicle
Nature of the road surface
Coefficient of friction between the road and vehicle contact point
Two non-collinear parallel equal forces acting in opposite direction
Balance each other
Constitute a moment
Constitute a couple
Constitute a moment of couple
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
Which of the following is not a vector quantity?
Weight
Velocity
Acceleration
Force
Which of the following statement is correct?
The kinetic energy of a body during impact remains constant.
The kinetic energy of a body before impact is equal to the kinetic energy of a body after impact.
The kinetic energy of a body before impact is less than the kinetic energy of a body after impact.
The kinetic energy of a body before impact is more than the kinetic energy of a body after impact.
The rate of doing work is known as
Potential energy
Kinetic energy
Power
None of these
The unit of force in S.I. units is
kilogram
Newton
Watt
Dyne
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
Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction
Along the plane
Horizontally
Vertically
At an angle equal to the angle of friction to the inclined plane
The moment of inertia of a thin disc of mass m and radius r, about an axis through its centre of gravity and perpendicular to the plane of the disc is
mr2/2
mr2/4
mr2/6
mr2/8
The centre of gravity of a right circular solid cone is at a distance of __________ from its base, measured along the vertical axis. (where h = Height of a right circular solid cone.)
h/2
h/3
h/4
h/6
The centre of gravity of a uniform lamina lies at
The centre of heavy portion
The bottom surface
The midpoint of its axis
All of the above
The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction.)
α = 45° + φ/2
α = 45° - φ/2
α = 90° + φ
α = 90° - φ
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)
Lami's theorem states that
Three forces acting at a point will be in equilibrium
Three forces acting at a point can be represented by a triangle, each side being proportional to force
If three forces acting upon a particle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium
If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two
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
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 units of moment of inertia of mass are
kg-m²
m²/kg.
kg/m²
kg/m
Non-coplanar non-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
Do not meet at one point but their lines of action lie on the same plane
None of the above
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
The moment of inertia of a square of side a about its diagonal is
a2/8
a3/12
a4/12
a4/16
The power developed by a body acted upon by a torque T Newton metre (N - m) and revolving at ω radian/s is given by
T.ω (in watts)
T.ω/60 (in watts)
T.ω/75 (in kilowatts)
T.ω/4500 (in kilowatts)
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
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