A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to
1.W
2.W sin (a + $)
3.Wtan(a + <|))
4.Wan(a-)
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Coulomb friction is the friction betweentwo dry surfaces
1.bodies having relative motion
2.two dry surfaces
3.two lubricated surfaces
4.solids and liquids
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In actual machinesmechanical advantage is unity
1.mechanical advantage is greater than velocity ratio
2.mechanical advantage is equal to velocity ratio
3.mechanical advantage is less than velocity ratio
4.mechanical advantage is unity
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Which of the following is not the unit of energy
1.kg m
2.kcal
3.wattr
4.watt hours
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. If three forces acting in one plane upon a rigid body keep it in equilibrium then they must eitherbe all parallelat least two of them must meet
1.meet in a point
2.be all parallel
3.at least two of them must meet
4.all the above are correct
Posted Date:-2021-10-04 11:47:52
72. Which one of the following statements is not correctnone of the above.
1.the tangent of the angle of friction is equal to coefficient of friction
2.the angle of repose is equal to angle of friction
3.the tangent of the angle of repose is equal to coefficient of friction
4.the sine of the angle of repose is equal to coefficient to friction
Posted Date:-2021-10-04 11:47:52
A body moves from rest with a constant acceleration of 5 m per sec. The distance covered in 5 sec is most nearly
1.38 m
2.62.5 m
3.6 m
4.124 m
Posted Date:-2021-10-04 11:47:52
A particle inside a hollow sphere of radius r having coefficient of friction -rr can rest upto height of
1.r/2
2.r/A
3.r/%
4.0.134 r
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A single force and a couple acting in the same plane upon a rigid body
1.balance each other
2.cannot balance each other
3.produce moment of a couple
4.are equivalent
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Angle oT friction is the
1.angle between normal reaction and the resultant of normal reaction and the limiting friction
2.ratio of limiting friction and normal reaction
3.he ratio of minimum friction force to the friction force acting when the body is just about to move
4.the ratio of minimum friction force to friction force acting when the body is in motion
Posted Date:-2021-10-04 11:47:52
Dynamic friction as compared to static friction ishas no correlation.
1.same
2.more
3.less
4.may be less of more depending on na-ture of surfaces and velocity
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Frictional force encountered after commencement of motion is calleddynamic friction.
1.post friction
2.limiting friction
3.kinematic friction
4.frictional resistance
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If a suspended body is struck at the centre of percussion then the pressure on die axis passing through the point of suspension will bezero
1.maximum
2.minimum
3.zero
4.infinity
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If three forces acting in different planes can be represented by a triangle these will be in
1.non-equilibrium
2.partial equilibrium
3.full equilibrium
4.unpredictable
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In ideal machines
1.mechanical advantage is greater than velocity ratio
2.mechanical advantage is equal to velocity ratio
3.mechanical advantage is less than velocity ratio
4.mechanical advantage is unity
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In the equation of virtual work following force is neglectedreaction at a point or an axis fixed in space around which a body is con-all of the above
1.reaction of any smooth surface with which the body is in contact
2.reaction of a rough surface of a body which rolls on it without slipping
3.reaction at a point or an axis fixed in space around which a body is con-
4.strained to turn
Posted Date:-2021-10-04 11:47:52
Kinetic friction is thethe friction force acting when the body is in motion
1.tangent of angle between normal reac-tion and the resultant of normal reac-tion and the limiting friction
2.ratio of limiting friction and normal reaction
3.the friction force acting when the body is just about to move
4.the friction force acting when the body is in motion
Posted Date:-2021-10-04 11:47:52
Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction
1.along the plane
2.horizontally
3.vertically
4.at an angle equal to the angle of fric?tion to the inclined plane
Posted Date:-2021-10-04 11:47:52
Limiting force of friction is theminimum force of friction.
1.tangent of angle between normal-reac-tion and the resultant of normal reac-tion and limiting friction
2.ratio of limiting friction and normal reaction
3.the friction force acting when the body is just about to move
4.the friction force acting when the body is in motion
Posted Date:-2021-10-04 11:47:52
On a ladder resting on smooth ground and leaning against vertical wall the force of friction will be
1.towards the wall at its upper end
2.away from the wall at its upper end
3.upwards at its upper end
4.downwards at its upper end
Posted Date:-2021-10-04 11:47:52
On the ladder resting on the ground and leaning against a smooth vertical wall the force of friction will be
1.downwards at its upper end
2.upwards at its upper end
3.perpendicular to the wall at its upper end
4.zero at its upper end
Posted Date:-2021-10-04 11:47:52
Pick up wrong statement about friction force for dry surfaces. Friction force is
1.proportional to normal load between the surfaces
2.dependent on the materials of contact surface
3.proportional to velocity of sliding
4.independent of the area of contact sur-faces
Posted Date:-2021-10-04 11:47:52
Tangent of angle of friction is equal to
1.kinetic friction
2.limiting friction
3.angle of repose
4.coefficient of friction
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The angle which an inclined plane makes with the horizontal when a body placed on it is about to move down is known as angle of
1.friction
2.limiting friction
3.repose
4.kinematic friction
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The C.G. of a plane lamina will not be at its geometrical centre in the case of a
1.right angled triangle
2.equilateral triangle
3.square
4.circle
Posted Date:-2021-10-04 11:47:52
The C.G. of a right circular solid cone of height h lies at the following distance from the base
1.h/2
2.J/3
3.h/6
4.h/4
Posted Date:-2021-10-04 11:47:52
The centre of percussion of a solid cylinder of radius r resting on a horizontal plane will be2r/3
1.r/2
2.2r/3
3.r/A
4.3r/2
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The co-efficient of friction depends upon
1.nature of surfaces
2. area of contact
3.shape of the surfaces
4.ail of the above.
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The coefficient of friction depends onnature of surface
1.area of contact
2.shape of surfaces
3.strength of surfaces
4.nature of surface
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The effort required to lift a load W on a screw jack with helix angle a and angle of friction
1.Wtan(a + <)>)
2.Wtan(a-<)>)
3.Wcos(a + )
4.Wsin(a + <(>)
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The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is
1.same
2.double
3.half
4.four times
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The necessary condition for forces to be in equilibrium is that these should beboth (a) and (b) aboveall be equal
1.coplanar
2.meet at one point ;
3.both (a) and (b) above
4.all be equal
Posted Date:-2021-10-04 11:47:52
The ratio of limiting friction and normal reaction is known as
1.coefficient of friction
2.angle of friction
3.angle of repose
4.sliding friction
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The resultant of the following three couples 20 kg force 0.5 m arm $ ve sense 30 kg force 1 m arm - ve sense 40 kg force 0.25 m arm + ve sense having arm of 0.5 m will be
1.20 kg - ve sense
2.20 kg + ve sense
3.10 kg + ve sense
4.10 kg - ve sense
Posted Date:-2021-10-04 11:47:52
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 oneellipsecircle
1.ellipse
2.hyperbola
3.parabola
4.circle
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