300 Important Engineering Mechanics MCQ Question and Answer | PDF Free Download
1.The linear velocity of a body rotating at ω rad/s along a circular path of radius r is given by
- Aω/r
- Bω.r
- Cω²/r
- Dω².r
2.Center of percussion is
- AThe point of C.G.
- BThe point of metacenter
- CThe point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
- DPoint of suspension
3.A smooth cylinder lying on its convex surface remains in __________ equilibrium.
- AStable
- BUnstable
- CNeutral
- DNone of these
4.According to law of triangle of forces
- AThree forces acting at a point will be in equilibrium
- BThree forces acting at a point can be represented by a triangle, each side being proportional to force
- CIf 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
- DIf three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two
5.The maximum mechanical advantage of a lifting machine is
- A1 + m
- B1 – m
- C1 / m
- Dm
6.According to Newton's first law of motion
- AEverybody continues in its state of rest or of uniform motion, in a straight line, unless it is acted upon by some external force
- BThe rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
- CTo every action, there is always an equal and opposite reaction
- DNone of the above
7.If rain is falling in the opposite direction of the movement of a pedestrian, he has to hold his umbrella
- AMore inclined when moving
- BLess inclined when moving
- CMore inclined when standing
- DLess inclined when standing
8.From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the centre of circular plate
- A0.5 cm
- B1.0 cm
- C1.5 cm
- D2.5 cm
9.The power developed by a body acted upon by a torque 'T' Newton meter (N - m) and revolving at ω radian/s is given by
- AT.ω (in watts)
- BT.ω/60 (in watts)
- CT.ω/75 (in kilowatts)
- DT.ω/4500 (in kilowatts)
10.Coefficient of friction is the
- AAngle between normal reaction and the resultant of normal reaction and the limiting friction
- BRatio of limiting friction and normal reaction
- CThe friction force acting when the body is just about to move
- DThe friction force acting when the body is in motion
11.For a self locking machine, the efficiency must be
- AEqual to 50%
- BLess than 50%
- CGreater than 50%
- D100%
12.During elastic impact, the relative velocity of the two bodies after impact is __________ the relative velocity of the two bodies before impact.
- AEqual to
- BEqual and opposite to
- CLess than
- DGreater than
13.Whenever a force acts on a body and the body undergoes a displacement, then
- AWork is said to be done
- BPower is being transmitted
- CBody has kinetic energy of translation
- DNone of these
14.In actual machines, mechanical advantage is _________ velocity ratio.
- AEqual to
- BLess than
- CGreater than
- DNone of these
15.The force, by which the body is attracted, towards the center of the earth, is called
- AImpulsive force
- BMass
- CWeight
- DMomentum
16.In order to completely specify angular displacement by a vector, it must fix
- ADirection of the axis of rotation
- BMagnitude of angular displacement
- CSense of angular displacement
- DAll of these
17.The three forces of 100 N, 200 N and 300 N have their lines of action parallel to each other but act in the opposite directions. These forces are known as
- ACoplanar concurrent forces
- BCoplanar non-concurrent forces
- CLike parallel forces
- DUnlike parallel forces
18.A screw jack used for lifting the loads is
- AA reversible machine
- BA non-reversible machine
- CAn ideal machine
- DNone of these
19.The velocity ratio of a simple wheel and axle with D and d as the diameters of effort wheel and load axle, is
- AD + d
- BD – d
- CD × d
- DD / d
20.A framed structure is perfect if it contains members equal to (Where, n = number of joints in a frame)
- A2n³
- B2n
- Cn²
- D3n²