The moment of inertia of a solid cylinder of mass m, radius r and length l about the longitudinal axis or polar axis is
mr2/2
mr2/4
mr2/6
mr2/8
Correct Answer :
A. mr2/2
Related Questions
The necessary condition for forces to be in equilibrium is that these should be
Coplanar
Meet at one point
Both (A) and (B) above
All be equal
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
Which of the following is not the unit of pressure?
kg/cm
Bar
Atmosphere
Newton
Limiting force of friction is the
Tangent of angle between normal reaction and the resultant of normal reaction and 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
Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
Area of the triangle
Twice the area of the triangle
Half the area of the triangle
None of these
A smooth cylinder lying on a __________ is in neutral equilibrium.
Curved surface
Convex surface
Horizontal surface
None of these
Which of the following are vector quantities?
Angular displacement
Angular velocity
Angular acceleration
All of these
According to Lamis theorem
The three forces must be equal
The three forces must be at 120° to each other
The three forces must be in equilibrium
If the three forces acting at a point are in equilibrium, then each force is proportional to the sine of the angle between the other two
For any system of coplanar forces, the condition of equilibrium is that the
Algebraic sum of the horizontal components of all the forces should be zero
Algebraic sum of the vertical components of all the forces should be zero
Algebraic sum of moments of all the forces about any point should be zero
All of the above
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
The unit of force in S.I. system of units is
Dyne
Kilogram
Newton
Watt
The forces, which meet at one point and their lines of action also lie on the same plane, are known as
Coplanar concurrent forces
Coplanar non-concurrent forces
Non-coplanar concurrent forces
Non-coplanar non-concurrent forces
The ratio of limiting friction and normal reaction is known as
Coefficient of friction
Angle of friction
Angle of repose
Sliding friction
The Cartesian equation of trajectory is (where u = Velocity of projection, α = Angle of projection, and x, y = Co-ordinates of any point on the trajectory after t seconds.)
y = (gx²/2u² cos²α) + x. tanα
y = (gx²/2u² cos²α) - x. tanα
y = x. tanα - (gx²/2u² cos²α)
y = x. tanα + (gx²/2u² cos²α)
Which of the following statement is correct in connection with projectiles?
A path, traced by a projectile in the space, is known as trajectory.
The velocity, with which a projectile is projected, is known as the velocity of projection.
The angle, with the horizontal, at which a projectile is projected, is known as angle of projection.
All of the above
The maximum mechanical advantage of a lifting machine is
1 + m
1 - m
1 / m
m
The frequency of oscillation of a compound pendulum is (where kG = Radius of gyration about the centroidal axis, and h = Distance between the point of suspension and C.G. of the body.)
2π. √(gh/kG² + h²)
2π. √(kG² + h²/gh)
1/2π. √(gh/kG² + h²)
1/2π. √(kG² + h²/gh)
The centre of gravity of a trapezium with parallel sides a and b lies at a distance of y from the base b, as shown in the below figure. The value of y is 
h [(2a + b)/(a + b)]
(h/2) [(2a + b)/(a + b)]
(h/3) [(2a + b)/(a + b)]
(h/3) [(a + b)/(2a + b)]
Which of the following is not the unit of work, energy and heat?
kcal
kg-m
kW-hr
h.p
Tangent of angle of friction is equal to
Kinetic friction
Limiting friction
Angle of repose
Coefficient of friction
Static friction is always __________ dynamic friction.
Equal to
Less than
Greater than
None of these
The maximum velocity of a particle moving with simple harmonic motion is
ω
ωr
ω2r
ω/r
Frictional force encountered after commencement of motion is called
Limiting friction
Kinematic friction
Frictional resistance
Dynamic friction
The motion of a wheel of a car is
Purely translation
Purely rotational
Combined translation and rotational
None of these
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)
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
The resultant of two equal forces P making an angle θ, is given by
2P sinθ/2
2P cosθ/2
2P tanθ/2
2P cotθ/2
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
The C.G. of a plane lamina will not be at its geometrical centre in the case of a
Right angled triangle
Equilateral triangle
Square
Circle
The resultant of the two forces P and Q is R. If Q is doubled, the new resultant is perpendicular to P. Then
P = Q
Q = R
Q = 2R
None of these