SBI PO - Engineering Mechanics 1000+ MCQ [Solved] PDF Download

1. The maximum frictional force which comes into play when a body just begins to slide over another surface is called
A. Limiting friction
B. Sliding friction
C. Rolling friction
D. Kinematic friction
Answer : A

2. The term 'Centroid' is
A. The same as centre of gravity
B. The point of suspension
C. The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
D. None of the above
Answer : A

3. The potential energy of a vertically raised body is __________ the kinetic energy of a vertically falling body.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : A

4. The moment of the force P about O as shown in the below figure is
A. P × OA
B. P × OB
C. P × OC
D. P × AC
Answer : C

5. In determining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than
A. Two members with unknown forces of the frame
B. Three members with unknown forces of the frame
C. Four members with unknown forces of the frame
D. Three members with known forces of the frame
Answer : B

6. 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
A. 1 m
B. 2 m
C. 3 m
D. 4 m
Answer : B

7. The impact between two lead spheres is approximately equal to an __________ impact.
A. Elastic
B. Inelastic
C. Solid
D. None of these
Answer : B

8. The unit of moment of inertia of an area is
A. kg-m²
B. kg-m-s²
C. kg/m²
D. m⁴
Answer : D

9. The periodic time (T) is given by (where, ? = Angular velocity of particle in rad/s.)
A. ?/2?
B. 2?/?
C. 2? × ?
D. ?/?
Answer : B

10. The range of a projectile is maximum, when the angle of projection is
A. 30°
B. 45°
C. 60°
D. 90°
Answer : B

11. The time of flight (t) of a projectile on an upward inclined plane is (where u = Velocity of projection, ? = Angle of projection, and ? = Inclination of the plane with the horizontal.)
A. t = g cos ?/2u sin (? - ?)
B. t = 2u sin (? - ?)/g cos ?
C. t = g cos ?/2u sin (? + ?)
D. t = 2u sin (? + ?)/g cos ?
Answer : B

12. The velocity ratio of a first system of pulleys with 4 pulleys is
A. 4
B. 8
C. 16
D. 20
Answer : C

13. The maximum height of a projectile on a horizontal plane, is
A. u² sin²?/2g
B. u² cos²?/2g
C. u² sin²?/g
D. u² cos²?/g
Answer : A

14. The bodies which rebound after impact are called
A. Inelastic bodies
B. Elastic bodies
C. Neither elastic nor inelastic bodies
D. None of these
Answer : B

15. The time of flight (t) of a projectile on a horizontal plane is given by
A. t = 2u. sin?/g
B. t = 2u. cos?/g
C. t = 2u. tan?/g
D. t = 2u/g.sin?
Answer : A

16. Non-coplanar non-concurrent forces are those forces which
A. Meet at one point, but their lines of action do not lie on the same plane
B. Do not meet at one point and their lines of action do not lie on the same plane
C. Do not meet at one point but their lines of action lie on the same plane
D. None of the above
Answer : B

17. The acceleration of a particle moving with simple harmonic motion, at any instant is given by
A. ?.y
B. ?².y
C. ?²/y
D. ?³.y
Answer : B

18. The force applied on a body of mass 100 kg to produce an acceleration of 5 m/s², is
A. 20 N
B. 100 N
C. 500 N
D. None of these
Answer : C

19. In order to determine the effects of a force, acting on a body, we must know
A. Magnitude of the force
B. Line of action of the force
C. Nature of the force i.e. whether the force is push or pull
D. All of the above
Answer : D

20. When a rigid body is suspended vertically, and it oscillates with a small amplitude under the action of the force of gravity, the body is known as
A. Simple pendulum
B. Compound pendulum
C. Torsional pendulum
D. Second's pendulum
Answer : B

21. If the gravitational acceleration at any place is doubled, then the weight of a body will be
A. g/2
B. g
C. ?2.g
D. 2g
Answer : D

23. A lead ball with a certain velocity is made to strike a wall, it falls down, but rubber ball of same mass and with same velocity strikes the same wall, it rebounds. Select the correct reason from the following:
A. Both the balls undergo an equal change in momentum
B. The change in momentum suffered by rubber ball is more than the lead ball
C. The change in momentum suffered by rubber ball is less than the lead ball
D. None of the above
Answer : B

24. The forces which meet at one point, but their lines of action __________ on the same plane, are Known as non-coplanar concurrent forces.
A. Lie
B. Do not lie
C. Either A or B
D. None of these
Answer : B

25. Two coplanar couples having equal and opposite moments
A. Balance each other
B. Produce a couple and an unbalanced force
C. Are equivalent
D. Cannot balance each other
Answer : D

26. The resultant of two forces P and Q acting at an angle ? is
A. ?(P² + Q² + 2PQ sin?)
B. ?(P² + Q² + 2PQ cos?)
C. ?(P² + Q² - 2PQ cos?)
D. ?(P² + Q² - 2PQ tan?)
Answer : B

27. In a single threaded worm and worm wheel, the number of teeth on the worm is 50. The diameter of the effort wheel is 100 mm and that of load drum is 50 mm. The velocity ratio is
A. 50
B. 100
C. 200
D. 400
Answer : B

28. If a body is acted upon by a number of coplanar non-concurrent forces, it may
A. Rotate about itself without moving
B. Move in any one direction rotating about itself
C. Be completely at rest
D. All of these
Answer : D

29. Which of the following is the example of lever of first order?
A. Arm of man
B. Pair of scissors
C. Pair of clinical tongs
D. All of the above
Answer : D

30. The force induced in the string BC due to the load W as shown in the below figure is
A. W sin?
B. W cos?
C. W tan?
D. W cot?
Answer : D

31. The forces, which meet at one point, but their lines of action do not lie in a plane, are called
A. Coplanar non-concurrent forces
B. Non-coplanar concurrent forces
C. Non-coplanar non-concurrent forces
D. Intersecting forces
Answer : B

32. Pick up the incorrect statement from the following:
A. The C.G. of a circle is at its centre
B. The C.G. of a triangle is at the intersection of its medians
C. The C.G. of a rectangle is at the intersection of its diagonals
D. The C.G. of a semicircle is at a distance of r/2 from the centre
Answer : D

33. Which of the following are vector quantities?
A. Angular displacement
B. Angular velocity
C. Angular acceleration
D. All of these
Answer : D

34. According to law of triangle of forces
A. Three forces acting at a point will be in equilibrium
B. Three forces acting at a point can be represented by a triangle, each side being proportional to force
C. If 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
D. If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two
Answer : C

35. In actual machines
A. Mechanical advantage is greater than velocity ratio
B. Mechanical advantage is equal to velocity ratio
C. Mechanical advantage is less than velocity ratio
D. Mechanical advantage is unity
Answer : C

36. A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
A. 5
B. 10
C. 20
D. 40
Answer : B

37. The friction experienced by a body, when in motion, is known as
A. Rolling friction
B. Dynamic friction
C. Limiting friction
D. Static friction
Answer : B

38. The algebraic sum of the resolved parts of a number of forces in a given direction is equal to the resolved part of their resultant in the same direction. This is known as
A. Principle of independence of forces
B. Principle of resolution of forces
C. Principle of transmissibility of forces
D. None of these
Answer : B

39. A force acting on a body may
A. Change its motion
B. Balance the other forces acting on it
C. Retard its motion
D. All of the above
Answer : D

40. Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its vertex and parallel to the base, is __________ than that passing through its C.G. and parallel to the base.
A. Nine times
B. Six times
C. Four times
D. Two times
Answer : A

41. The maximum mechanical advantage of a lifting machine is
A. 1 + m
B. 1 - m
C. 1 / m
D. m
Answer : C

42. The coefficient of restitution for inelastic bodies is
A. Zero
B. One
C. Between zero and one
D. More than one
Answer : A

43. 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
A. Static friction
B. Dynamic friction
C. Limiting friction
D. Coefficient of friction
Answer : C

44. In order to double the period of simple pendulum, the length of the string should be
A. Halved
B. Doubled
C. Quadrupled
D. None of these
Answer : C

45. 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
A. 15 N and 5 N
B. 20 N and 5 N
C. 15 N and 15 N
D. None of these
Answer : A

46. The bellow figure shows the three coplanar forces P, Q and R acting at a point O. If these forces are in equilibrium, then
A. P/sin ? = Q/sin ? = R/sin ?
B. P/sin ? = Q/sin ? = R/sin ?
C. P/sin ? = Q/sin ? = R/sin ?
D. P/sin ? = Q/sin ? = R/sin ?
Answer : B

47. Forces are called coplanar when all of them acting on body lie in
A. One point
B. One plane
C. Different planes
D. Perpendicular planes
Answer : B

48. The unit of angular acceleration is
A. N-m
B. m/s
C. m/s2
D. rad/s2
Answer : D

49. Coulomb friction is the friction between
A. Bodies having relative motion
B. Two dry surfaces
C. Two lubricated surfaces
D. Solids and liquids
Answer : A

50. 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
A. Coplanar concurrent forces
B. Coplanar non-concurrent forces
C. Like parallel forces
D. Unlike parallel forces
Answer : D