Engineering Mechanics 1000+ MCQ with answer for XAT

1. When the lift is moving upwards with some acceleration, the pressure exerted by a man is __________ to its acceleration.
A. Directly proportional
B. Inversely proportional
C. Cube root
D. None of these
Answer : A

2. 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

3. The law of motion involved in the recoil of gun is
A. Newton's first law of motion
B. Newton's second law of motion
C. Newton's third law of motion
D. None of these
Answer : C

4. Angle of friction is the
A. Angle between normal reaction and the resultant of normal reaction and the limiting friction
B. Ratio of limiting friction and normal reaction
C. The ratio of minimum friction force to the friction force acting when the body is just about to move
D. The ratio of minimum friction force to friction force acting when the body is in motion
Answer : A

5. The velocity of a particle moving with simple harmonic motion is __________ at the mean position.
A. Zero
B. Minimum
C. Maximum
D. None of these
Answer : C

6. The velocity ratio of a single purchase crab winch can be increased by
A. Increasing the length of the handle
B. Increasing the radius of the load drum
C. Increasing the number of teeth of the pinion
D. All of the above
Answer : A

7. 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

8. Which of the following is a vector quantity?
A. Energy
B. Mass
C. Momentum
D. Angle
Answer : C

9. The minimum force required to slide a body of weight W on a rough horizontal plane is
A. W sin?
B. W cos?
C. W tan?
D. None of these
Answer : C

10. Which one of the following statements is not correct?
A. The tangent of the angle of friction is equal to coefficient of friction
B. The angle of repose is equal to angle of friction
C. The tangent of the angle of repose is equal to coefficient of friction
D. The sine of the angle of repose is equal to coefficient to friction
Answer : D

11. 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

12. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to
A. 25
B. 50
C. 100
D. 250
Answer : B

13. 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

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

15. Forces are called concurrent when their lines of action meet in
A. One point
B. Two points
C. Plane
D. Perpendicular planes
Answer : A

16. 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
A. Friction
B. Limiting friction
C. Repose
D. Kinematic friction
Answer : C

17. When a body of mass m attains a velocity v from rest in time t, then the kinetic energy of translation is
A. mv²
B. mgv²
C. 0.5 mv²
D. 0.5 mgv²
Answer : C

18. A body of weight W is required to move up on rough inclined plane whose angle of inclination with the horizontal is ?. The effort applied parallel to the plane is given by (where ? = tan? = Coefficient of friction between the plane and the body.)
A. P = W tan?
B. P = W tan (? + ?)
C. P = W (sin? + ?cos?)
D. P = W (cos? + ?sin?)
Answer : C

19. In a framed structure, as shown in the below figure, the force in the member AB is __________ the force in member AC.
A. Half
B. Equal to
C. Double
D. None of these
Answer : A

20. The C.G. of a right circular solid cone of height h lies at the following distance from the base
A. h/2
B. J/3
C. h/6
D. h/4
Answer : D

21. On the ladder resting on the ground and leaning against a smooth vertical wall, the force of friction wll be
A. Downwards at its upper end
B. Upwards at its upper end
C. Perpendicular to the wall at its upper end
D. Zero at its upper end
Answer : D

22. Concurrent forces are those forces whose lines of action
A. Lie on the same line
B. Meet at one point
C. Meet on the same plane
D. None of these
Answer : B

23. The moment of a force
A. Is the turning effect produced by a force, on the body, on which it acts
B. Is equal to the product of force acting on the body and the perpendicular distance of a point and the line of action of the force
C. Is equal to twice the area of the triangle, whose base is the line representing the force and whose vertex is the point, about which the moment is taken
D. All of the above
Answer : D

24. 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

25. A pendulum which executes one beat per second is known as
A. Simple pendulum
B. Compound pendulum
C. Torsional pendulum
D. Second's pendulum
Answer : D

26. 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

27. Static friction is always __________ dynamic friction.
A. Equal to
B. Less than
C. Greater than
D. None of these
Answer : C

28. Limiting force of friction is the
A. Tangent of angle between normal reaction and the resultant of normal reaction and limiting friction
B. Ratio of limiting friction and normal reaction
C. The friction force acting when the body is just about to move
D. The friction force acting when the body is in motion
Answer : C

29. If the masses of both the bodies, as shown in the below figure, are doubled, then the acceleration in the string will be
A. Same
B. Half
C. Double
D. None of these
Answer : A

30. The loss of kinetic energy during inelastic impact, is given by (where m₁ = Mass of the first body, m₂ = Mass of the second body, and u₁ and u₂ = Velocities of the first and second bodies respectively.)
A. [m? m?/2(m? + m?)] (u? - u?)²
B. [2(m? + m?)/m? m?] (u? - u?)²
C. [m? m?/2(m? + m?)] (u?² - u?²)
D. [2(m? + m?)/m? m?] (u?² - u?²)
Answer : A

31. Tangent of angle of friction is equal to
A. Kinetic friction
B. Limiting friction
C. Angle of repose
D. Coefficient of friction
Answer : D

32. If u₁ and u₂ are the velocities of two moving bodies in the same direction before impact and v₁ and v₂ are their velocities after impact, then coefficient of restitution is given by
A. (v₁ - v₂)/(u₁ - u₂)
B. (v? - v?)/(u₁ - u₂)
C. (u₁ - u₂)/(v₁ - v₂)
D. (u? + u?)/(v? + v?)
Answer : B

33. 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

34. The forces, whose lines of action are parallel to each other and act in the same directions, are known as
A. Coplanar concurrent forces
B. Coplanar non-concurrent forces
C. Like parallel forces
D. Unlike parallel forces
Answer : C

35. One joule means that
A. Work is done by a force of 1 N when it displaces a body through 1 m
B. Work is done by a force of 1 kg when it displaces a body through 1 m
C. Work is done by a force of 1 dyne when it displaces a body through 1 cm
D. Work is done by a force of 1 g when it displaces a body through 1 cm
Answer : A

36. Efficiency of a screw jack is given by (where ? = Helix angle, and ? = Angle of friction.)
A. tan(? + ?)/tan?
B. tan?/tan (? + ?)
C. tan(? - ?)/tan?
D. None of these
Answer : B

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

38. 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

39. Coefficient of friction is the
A. Angle between normal reaction and the resultant of normal reaction and the limiting friction
B. Ratio of limiting friction and normal reaction
C. The friction force acting when the body is just about to move
D. The friction force acting when the body is in motion
Answer : B

40. The resultant of two forces P and Q (such that P > Q) acting along the same straight line, but in opposite direction, is given by
A. P + Q
B. P - Q
C. P / Q
D. Q / P
Answer : B

41. 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

42. The moment of inertia of a square of side (a) about an axis through its centre of gravity is
A. a⁴/4
B. a⁴/8
C. a⁴/12
D. a⁴/36
Answer : C

43. 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

44. Which of the following do not have identical dimensions?
A. Momentum and impulse
B. Torque and energy
C. Torque and work
D. Moment of a force and angular momentum.
Answer : D

45. The matter contained in a body, is called
A. Impulsive force
B. Mass
C. Weight
D. Momentum
Answer : B

46. 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

47. 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

48. A ladder is resting on a rough ground and leaning against a smooth vertical wall. The force of friction will act
A. Downward at its upper end
B. Upward at its upper end
C. Zero at its upper end
D. Perpendicular to the wall at its upper end
Answer : C

49. The angle of inclination of the plane at which the body begins to move down the plane, is called
A. Angle of friction
B. Angle of repose
C. Angle of projection
D. None of these
Answer : A

50. D' Alembert's principle is used for
A. Reducing the problem of kinetics to equivalent statics problem
B. Determining stresses in the truss
C. Stability of floating bodies
D. Designing safe structures
Answer : A