300 Important Engineering Mechanics MCQ Question and Answer | PDF Free Download
1.Which of the following is an equation of linear motion?(where, u and v = Initial and final velocity of the body, a = Acceleration of the body, and s = Displacement of the body in time t seconds.)
- Av = u + a.t
- Bs = u.t + ½ a.t2
- Cv2 = u2 + 2a.s
- DAll of these
2.Which is the correct statement about law of polygon of forces?
- AIf any number of forces acting at a point can be represented by the sides of a polygon taken in order, then the forces are in equilibrium
- BIf any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon, then the forces are in equilibrium
- CIf a polygon representing forces acting at a point is closed then forces are in equilibrium
- DIf any number of forces acting at a point can be represented in direction and magnitude by the sides of a polygon taken in order, then the forces are in equilibrium
3.A machine having an efficiency less than 50%, is known as
- AReversible machine
- BNon-reversible machine
- CNeither reversible nor non-reversible machine
- DIdeal machine
4.In order to determine the effects of a force, acting on a body, we must know
- AMagnitude of the force
- BLine of action of the force
- CNature of the force i.e. whether the force is push or pull
- DAll of the above
5.The process of finding out the resultant force is called __________ of forces.
- AComposition
- BResolution
- CDecomposition
- DNone of these
6.The principle of transmissibility of forces states that, when a force acts upon a body, its effect is
- ASame at every point on its line of action
- BDifferent at different points on its line of action
- CMinimum, if it acts at the center of gravity of the body
- DMaximum, if it acts at the center of gravity of the body
7.A machine having an efficiency greater than 50%, is known as
- AReversible machine
- BNon-reversible machine
- CNeither reversible nor non-reversible machine
- DIdeal machine
8.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.)
- AP = mW – C
- BP = m/W + C
- CP = mW + C
- DP = C – mW
9.The acceleration of a particle moving with simple harmonic motion, at any instant is given by
- Aω.y
- Bω2.y
- Cω2/y
- Dω3.y
10.The minimum force required to slide a body of weight 'W' on a rough horizontal plane is
- AW sinθ
- BW cosθ
- CW tanθ
- DNone of these
11.When a body of mass moment of inertia 'I' (about a given axis) is rotated about that axis with an angular velocity to, then the kinetic energy of rotation is
- AIω
- BIω2
- C0.5 Iω
- D0.5 Iω2
12.Tangent of angle of friction is equal to
- AKinetic friction
- BLimiting friction
- CAngle of repose
- DCoefficient of friction
13.A single force and a couple acting in the same plane upon a rigid body
- ABalance each other
- BCannot balance each other
- CProduce moment of a couple
- DAre equivalent
14.Two balls of equal mass and of perfectly elastic material are lying on the floor. One of the balls with velocity ‘v’ is made to strike the second ball. Both the balls after impact will move with a velocity
- Av
- Bv/2
- Cv/4
- Dv/8
15.Frictional force encountered after commencement of motion is called
- ALimiting friction
- BKinematic friction
- CFrictional resistance
- DDynamic friction
16.In a screw jack, the effort required to lower the load is __________ the effort required to raise the same load.
- ALess than
- BEqual to
- CMore than
- DNone of these
17.If three forces acting in one plane upon a rigid body, keep it in equilibrium, then they must either
- AMeet in a point
- BBe all parallel
- CAt least two of them must meet
- DAll the above are correct
18.In actual machines
- AMechanical advantage is greater than velocity ratio
- BMechanical advantage is equal to velocity ratio
- CMechanical advantage is less than velocity ratio
- DMechanical advantage is unity
19.The range of a projectile is maximum, when the angle of projection is
- A30°
- B45°
- C60°
- D90°
20.The time of flight (t) of a projectile on a horizontal plane is given by
- At = 2u. sinα/g
- Bt = 2u. cosα/g
- Ct = 2u. tanα/g
- Dt = 2u/g.sinα