300 Important Engineering Mechanics MCQ Question and Answer | PDF Free Download
1.Two coplanar couples having equal and opposite moments
- ABalance each other
- BProduce a couple and an unbalanced force
- CAre equivalent
- DCannot balance each other
2.If a number of forces are acting at a point, their resultant will be inclined at an angle 'θ' with the horizontal, such that
- Atanθ = ΣH/ΣV
- Btanθ = ΣV/ΣH
- Ctanθ = ΣV × ΣH
- Dtanθ = √(ΣV + ΣH)
3.The Efficiency of a screw jack is given by (where α = Helix angle, and φ = Angle of friction.)
- Atan(α + φ)/tanα
- Btanα/tan (α + φ)
- Ctan(α - φ)/tanα
- DNone of these
4.The efficiency of a screw jack is maximum, when (where α = Helix angle, and φ = Angle of friction.)
- Aα = 45° + φ/2
- Bα = 45° - φ/2
- Cα = 90° + φ
- Dα = 90° - φ
5.The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ √(gra/h)
- ALess than
- BGreater than
- CEqual to
- DNone of these
6.Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, is
- ABh3/4
- BBh3/8
- CBh3/12
- DBh3/36
7.The unit of work or energy in S.I. units is
- ANewton
- BPascal
- CWatt
- DJoule
8.In order to double the period of simple pendulum, the length of the string should be
- AHalved
- BDoubled
- CQuadrupled
- DNone of these
9.A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
- A5
- B10
- C20
- D40
10.Two like parallel forces are acting at a distance of 24 mm apart and their resultant is 20 N. It the line of action of the resultant is 6 mm from any given force, the two forces are
- A15 N and 5 N
- B20 N and 5 N
- C15 N and 15 N
- DNone of these
11.The moment of inertia of a thin spherical shell of mass m and radius r, about its diameter is
- Amr²/3
- B2mr²/3
- C2mr²/5
- D3mr²/5
12.The centre of gravity a T-section 100 mm × 150 mm × 50 mm from its bottom is
- A50 mm
- B75 mm
- C87.5 mm
- D125 mm
13.The unit of moment of inertia of mass are
- Akg-m²
- Bm²/kg
- Ckg/m²
- Dkg/m
14.The centre of percussion of the homogeneous rod of length ‘L’ suspended at the top will be
- AL/2
- BL/3
- C3L/4
- D2L/3
15.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
- A1 m
- B2 m
- C3 m
- D4 m
16.If a number of forces act simultaneously on a particle, it is possible
- ANot a replace them by a single force
- BTo replace them by a single force
- CTo replace them by a single force through C.G.
- DTo replace them by a couple
17.If a rigid body is in equilibrium under the action of three forces, then
- AThese forces are equal
- BThe lines of action of these forces meet in a point
- CThe lines of action of these forces are parallel
- DBoth (B) and (C) above
18.The total motion possessed by a body, is called
- AImpulsive force
- BMass
- CWeight
- DMomentum
19.Moment of inertia is the
- ASecond moment of force
- BSecond moment of area
- CSecond moment of mass
- DAll of thes
20.The maximum efficiency of a screw jack is
- A(1 - sinφ)/(1 + sinφ)
- B(1 + sinφ)/(1 - sinφ)
- C(1 - tanφ)/(1 + tanφ)
- D(1 + tanφ)/(1 - tanφ)