1000+ Applied Mechanics and Graphic Statics MCQ for SSC CGL [Solved]

1. The following is not a law of static friction:
A. The force of friction always acts in a direction opposite to that in which the body tends to move
B. The force of friction is dependent upon the area of contact
C. The force of friction depends upon the roughness of the surface
D. The magnitude of the limiting friction bears a constant ratio to the normal reaction between two surfaces
Answer : A

2. The unit of impulse, is
A. kg.m/sec
B. kg.m/sec
C. kg.m/sec²
D. kg.m/sec
Answer : A

3. The units of inertia of mass are
A. kg/m
B. kg/m²
C. m⁴
D. kg-m²
Answer : D

4. The reaction at the support A of the beam shown in below figure is
A. 2 t
B. 5.8 t
C. 0.2 t
D. 3.5 t
Answer : A

5. The product of mass and velocity of a moving a body, is called
A. Moment
B. Momentum
C. Power
D. Impulse
Answer : B

6. M.I. of a thin ring (external diameter D, internal diameter d) about an axis perpendicular to the plane of the ring, is
A. ?/64 (D⁴ + d⁴)
B. ?/32 (D⁴ - d⁴)
C. ?/32 (D⁴ + d⁴)
D. ?/32 (D⁴ × d⁴)
Answer : B

7. If two equal forces of magnitude P act at an angle ?, their resultant, will be
A. P cos ?/2
B. 2P sin ?/2
C. P tan ?/2
D. 2P cos ?/2
Answer : D

8. At a given instant ship A is travelling at 6 km/h due east and ship B is travelling at 8 km/h due north. The velocity of B relative to A is
A. 7 km/hrs
B. 2 km/hrs
C. 1 km/hrs
D. 10 km/hrs
Answer : D

9. Pick up the correct statement from the following:
A. If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities
B. If a sphere impinges directly on an equal sphere which is at rest, then a fraction ½(1 - e2) the original kinetic energy is lost by the impact
C. If two equal spheres which are perfectly elastic impinge at right angles, their direction after impact will still be at right angles
D. All the above
Answer : D

10. An ordinate in a funicular polygon represents
A. Shear force
B. Resultant force
C. Bending moment
D. Equilibrium
Answer : C

11. A shell travelling with a horizontal velocity of 100 m/sec explodes and splits into two parts, one of mass 10 kg and the other of 15 kg. The 15 kg mass drops vertically downward with initial velocity of 100 m/sec and the 10 kg mass begins to travel at an angle to the horizontal of tan1 x, where x is
A. 3/4
B. 4/5
C. 5/3
D. 3/5
Answer : D

12. When a body slides down an inclined surface, the acceleration (f) of the body, is given by
A. f = g
B. f = g sin ?
C. f = g cos ?
D. f = g tan ?
Answer : B

13. The equation of motion of a particle starting from rest along a straight line is x = t³ - 3t²+ 5. The ratio of the accelerations after 5 sec and 3 sec will be
A. 2
B. 3
C. 4
D. 5
Answer : @

14. Moment of inertia of a squares of side b about an axis through its centre of gravity, is
A. b³/4
B. b⁴/12
C. b⁴/3
D. b⁴/8
Answer : B

15. The mechanical advantage of an ideal machine is 100. For moving the local through 2 m, the effort moves through
A. 0.02 m
B. 2 m
C. 2.5 m
D. 20 m
Answer : A

16. When a body moves round a fixed axis, it has
A. A rotary motion
B. A circular motion
C. A translatory
D. A rotary motion and translatory motion
Answer : B

17. One Newton is equivalent to
A. 10⁵ dyne
B. 10⁶ dyne
C. 10⁷ dyne
D. 10⁸ dyne
Answer : A

18. The unit of force in C.G.S. system of units, is called
A. Dyne
B. Newton
C. Kg
D. All the above
Answer : A

19. The velocity of a moving body, is
A. A vector quantity
B. A scalar quantity
C. A scalar as well as a vector quantity
D. None of these
Answer : A

20. If a ball which is dropped from a height of 2.25 m on a smooth floor attains the height of bounce equal to 1.00 m, the coefficient of the restitution between the ball and floor, is
A. 0.25
B. 0.50
C. 0.67
D. 0.33
Answer : B

21. Newton's law of Collision of elastic bodies states that when two moving bodies collide each other, their velocity of separation
A. Is directly proportional to their velocity of approach
B.C. Bears a constant ratio to their velocity of approach
D. Is equal to the sum of their velocities of approach
Answer : C

22. A ball of mass 1 kg moving with a velocity of 2 m/sec collides a stationary ball of mass 2 kg and comes to rest after impact. The velocity of the second ball after impact will be
A. Zero
B. 0.5 m/sec
C. 1.0 m/sec
D. 2.0 m/sec
Answer : C

23. The masses of two balls are in the ratio of 2 : 1 and their respective velocities are in the ratio of 1 : 2 but in opposite direction before impact. If the coefficient of restitution is ½, the velocities of separation of the balls will be equal to
A. Original velocity in the same direction
B. Half the original velocity in the same direction
C. Half the original velocity in the opposite direction
D. Original velocity in the opposite direction
Answer : D

24. In case of S.H.M. the period of oscillation (T), is given by
A. T = 2?/?²
B. T = 2?/?
C. T = 2/?
D. T = ?/2?
Answer : B

25. Engineer's units of force, is
A. Newton in absolute units
B. Dyne in absolute units
C. Newton and dyne in absolute units
D. All the above
Answer : A

26. Power can be expressed as
A. Work/energy
B. Work/time
C. Work × time
D. Work/distance
Answer : B

27. The Centre of gravity of a 10 × 15 × 5 cm T-section from its bottom, is
A. 7.5 cm
B. 5.0 cm
C. 8.75 cm
D. 7.85 cm
Answer : C

28. If a particle is projected inside a horizontal tunnel which is 554 cm high with a velocity of 60 m per sec, the angle of projection for maximum range, is
A. 8°
B. 9°
C. 10°
D. 11°
Answer : C

29. If ? and u are the angle of projection and initial velocity of a projectile respectively, the horizontal range of the projectile, is
A. u² sin ?/g
B. u² sin² ?/g
C. u² sin ?/2g
D. u² sin² ?/2g
Answer : A

30. If the resultant of two forces has the same magnitude as either of the force, then the angle between the two forces is
A. 30°
B. 45°
C. 60°
D. 120°
Answer : D

31. A particle is dropped from a height of 3 m on a horizontal floor, which has a coefficient of restitution with the ball of 1/2. The height to which the ball will rebound after striking the floor is
A. 0.5 m
B. 0.75 m
C. 1.0 m
D. 1.5 m
Answer : B

32. The shape of a suspended cable for a uniformly distributed load over it is
A. Circular
B. Parabolic
C. Catenary
D. Cubic parabola
Answer : B

33. The centre of gravity of the trapezium as shown in below figure from the side is at a distance of

A. (h/3) × [(b + 2a)/(b + a)]
B. (h/3) × [(2b + a)/(b + a)]
C. (h/2) × [(b + 2a)/(b + a)]
D. (h/2) × [(2b + a)/(b + a)]
Answer : A

34. The following is in unstable equilibrium
A. A uniform solid cone resting on a generator on a smooth horizontal plane
B. A uniform solid cone resting on its base on a horizontal plane
C. A solid cube resting on one edge
D. A satellite encircling the earth
Answer : C

35. The centre of gravity of a quadrant of a circle lies along its central radius at a distance of
A. 0.2 R
B. 0.4 R
C. 0.3 R
D. 0.6 R
Answer : D

36. A weight W is suspended at the free end of a light member hinged to a vertical wall. If the angle of inclination of the member with the upper wall is ?°, the force introduced in the member, is
A. W sec ?
B. W cos ?
C. W sin ?
D. W cosec ?
Answer : A

37. One end of an elastic string of natural length / and modulus X is kept fixed while to the other end is attached a particle of mass m which is hanging freely under gravity. The particle is pulled down vertically through a distance x, held at rest and then released. The motion is
A. A simple harmonic motion
B. A rectilinear motion with constant speed
C. A damped oscillatory motion
D. None of the above
Answer : A

38. The force polygon representing a set of forces in equilibrium is a
A. Triangle
B. Open polygon
C. Closed polygon
D. Parallelogram
Answer : C

39. Two loads of 50 kg and 75 kg are hung at the ends of a rope passing over a smooth pulley shown in below figure. The tension in the string is:
A. 50 kg
B. 75 kg
C. 25 kg
D. 60 kg
Answer : D

40. According to Law of Triangle of Forces
A. Three forces acting at a point, can be rep-resented by the sides of a triangle, each side being in proportion to the force
B. Three forces acting along the sides of a triangle are always in equilibrium
C. If three forces acting on a, point can be represented in magnitude and direction, by the sides of a triangle taken in order, these will be in equilibrium D. If the forces acting on a particle be represented in magnitude and direction by the two sides of a triangle taken in order, their resultant will be represented in magnitude and direction by the third side of the triangle, taken in opposite order
Answer : D

41. A heavy ladder resting on a floor and against a vertical wall may not be in equilibrium, if
A. Floor is smooth and the wall is rough
B. Floor is rough and the wall is smooth
C. Floor and wall both are smooth surfaces
D. Floor and wall both are rough surfaces
Answer : C

42. The rotational velocity of a satellite is increased by 450 m per second if its launch is done from equator
A. Eastward
B. Northward
C. Westward
D. Southward
Answer : A

43. A marble ball is rolled on a smooth floor of a room to hit a wall. If the time taken by the ball in returning to the point of projection is twice the time taken in reaching the wall, the coefficient of restitution between the ball and the wall, is
A. 0.25
B. 0.50
C. 0.75
D. 1.0
Answer : B

44. The condition for a lifting machine to be reversible is that its efficiency should be
A. Less than 50%
B. More than 50%
C. More than 66.67%
D. Equal to 100%
Answer : B

45. The condition of equilibrium for any system of forces in a plane is
A. That polygon of forces must close
B. That resultant couple must be zero
C. Both (A) and (B)
D. None of the above
Answer : C

46. One Joule is equivalent to
A. 9.81 Newton metre
B. 1 Newton metre
C. 1 kg wt metre
D. 1 dyne metre
Answer : B

47. The resultant of two forces acting at right angles is ?34 kg and acting at 60° is 70 kg. The forces are
A. 1 kg and 4 kg
B. 2 kg and 3 kg
C. ?3 kg and ?5 kg
D. 3 kg and 5 kg
Answer : D

48. From a circular plate of a diameter 6 cm is cut out a circle whose diameter is equal to the radius of the plate. The C.G. of the remainder from the centre of circular plate is at a distance of
A. 2.0 cm
B. 1.5 cm
C. 1.0 cm
D. 0.5 cm
Answer : D

49. Newtons Law of Motion is:
A. Everybody continues in its state of rest or of uniform motion in a straight line, unless it is acted upon by some external force
B. The rate of change of momentum is directly proportional to the impressed force, and takes place in the same direction, in which the force acts
C. To every action, there is always an equal and opposite reaction
D. All the above
Answer : D

50. Pick up the correct statement from the following:
A. Nature plays an important role in the launch of a satellite
B. The earth's gravity reduces the speed of a satellite by 32 km per second
C. The gravitational force relents as the satellite climbs higher
D. All the above
Answer : D