The centre of gravity of a quadrant of a circle lies along its central radius (r) at a distance of
0.5r
0.6 r
0.7 r
0.8 r
Correct Answer :
B. 0.6 r
Related Questions
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 maximum frictional force which comes into play when a body just begins to slide over another surface is called
Limiting friction
Sliding friction
Rolling friction
Kinematic friction
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
Which of the following is not the unit of power?
kW (kilowatt)
hp (horse power)
kcal/sec
kcal/kg sec
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
A rubber ball is dropped from a height of 2 m. If there is no loss of velocity after rebounding, the ball will rise to a height of
1 m
2 m
3 m
4 m
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
A force is completely defined when we specify
Magnitude
Direction
Point of application
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
Which of the following is the locus of a point that moves in such a manner that its distance from a fixed point is equal to its distance from a fixed line multiplied by a constant greater than one
Ellipse
Hyperbola
Parabola
Circle
The centre of gravity of a triangle lies at the point of
Concurrence of the medians
Intersection of its altitudes
Intersection of bisector of angles
Intersection of diagonals
Effect of a force on a body depends upon
Magnitude
Direction
Position or line of action
All of the above
A couple produces
Translatory motion
Rotational motion
Combined translatory and rotational motion
None of the above
When trying to turn a key into a lock, following is applied
Coplanar force
Non-coplanar forces
Moment
Couple
Forces are called coplanar when all of them acting on body lie in
One point
One plane
Different planes
Perpendicular planes
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.
A machine having an efficiency less than 50%, is known as
Reversible machine
Non-reversible machine
Neither reversible nor non-reversible machine
Ideal machine
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 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
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
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
A particle inside a hollow sphere of radius r, having coefficient of friction μ can rest up to height of
r/2
r/A
r/3
0.134 r
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
A spherical body is symmetrical about its perpendicular axis. According to Routh's rule, the moment of inertia of a body about an axis passing through its centre of gravity is (where, M = Mass of the body, and S = Sum of the squares of the two semi-axes.)
MS/3
MS/4
MS/5
None of these
Which of the following is not the unit of distance?
Angstrom
Light year
Micron
Milestone
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 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 forces which do not meet at one point and their lines of action do not lie on the same plane are known as
Coplanar concurrent forces
Coplanar non-concurrent forces
Non-coplanar concurrent forces
None of these
When the spring of a watch is wound, it will possess
Strain energy
Kinetic energy
Heat energy
Electrical energy
In ideal machines, mechanical advantage is __________ velocity ratio.
Equal to
Less than
Greater than
None of these