1000+ Applied Mechanics and Graphic Statics Multiple Choice Question Answer [Solved]

1. The forces which meet at one point and have their lines of action in different planes are called
A. Coplanar non-concurrent forces
B. Non-coplanar concurrent forces
C. Non-coplanar non-current forces
D. Intersecting forces
Answer : B

2. A smooth cylinder lying on its convex surface remains
A. In stable equilibrium
B. In unstable equilibrium
C. In neutral equilibrium
D. Out of equilibrium
Answer : B

3. According to Kennedy's theorem, if three bodies have plane motions, their instantaneous centres lie on
A. A point
B. A straight line
C. Two straight lines
D. A triangle
Answer : B

4. A projectile is thrown at an angle ? to the horizontal with velocity v. It will have the maximum centripetal acceleration
A. At the start
B. At the top of the trajectory
C. As it strikes the ground
D. Elsewhere
Answer : A

5. A pilot flies a small plane in a vertical loop of radius r. At the top of its trajectory he experiences weightlessness. If the acceleration due to gravity is g, the speed of the plane at the top of its trajectory would be
A. Zero
B. Infinite
C. gr
D. 2gr
Answer : C

6. The motion of a bicycle wheel is
A. Translatory
B. Rotary
C. Rotary and translatory
D. Curvilinear
Answer : C

7. ? is coefficient of friction. A wheeled vehicle travelling on a circular level track will slip and overturn simultaneously if the ratio of its wheel distance to the height of its centroid, is
A. ?
B. 2?
C. 3?
D. ½?
Answer : B

8. In SI units, the units of force and energy are respectively
A. Newton and watt
B. Dyne and erg
C. Newton and joule
D. kg wt and joule
Answer : C

9. The resultant of the forces acting on a body will be zero if the body
A. Rotates
B. Moves with variable velocity in a straight line
C. Moves along a curved path
D. Does not move at all
Answer : D

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

11. 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

12. A projectile is fired at an angle ? to the vertical. Its horizontal range will be maximum when ? is
A. 0°
B. 30°
C. 45°
D. 90°
Answer : C

13. A glass ball is shot to hit a wall from a point on a smooth floor. If the ball returns back to the point of projection in twice the time taken in reaching the wall, the coefficient of restitution between the glass ball and the wall is
A. 0.25
B. 0.33
C. 0.40
D. 0.50
Answer : D

14. A cable loaded with 0.5 tonne per horizontal metre span is stretched between supports in the same horizontal line 400 m apart. If central dip is 20 m, the minimum tension in the cable, will be
A. 200 tonnes at the centre
B. 500 tonnes at the centre
C. 200 tonnes at the right support
D. 200 tonnes at the left support
Answer : B

15. On a ladder resisting on a smooth ground and leaning against a rough vertical wall, the force of friction acts
A. Towards the wall at its upper end
B. Away from the wall at its upper end
C. Upwards at its upper end
D. Downwards at its upper end
Answer : C

16. The moment of inertia of a hollow circular section whose external diameter is 8 cm and internal diameter is 6 cm, about centroidal axis, is
A. 437.5 cm⁴
B. 337.5 cm⁴
C. 237.5 cm⁴
D. 137.5 cm⁴
Answer : D

17. If the tension in a cable supporting a lift moving upwards is twice the tension when the lift is moving downwards, the acceleration of the lift, is
A. g/2
B. g/3
C. g/4
D. g/5
Answer : B

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

19. The C.G. of a hemisphere from its base measured along the vertical radius is at a distance of
A. 4R/3?
B. 3R/8
C. 3?R/4
D. 8R/3
Answer : B

20. 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

21. If a spherical body is symmetrical about its perpendicular axes, the moment of inertia of the body bout an axis passing through its centre of gravity as given by Routh's rule is obtained by dividing the product of the mass and the sum of the squares of two semi-axes by n. Where, n is
A. 2
B. 3
C. 4
D. 5
Answer : D

22. The phenomenon of collision of two elastic bodies takes place because bodies
A. Immediately after collision come momentarily to rest
B. Tend to compress each other till they are compressed maximum possible
C. Attempt to regain its original shape due to their elasticities
D. All the above
Answer : D

23. 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

24. Minimum potential energy of a system will be in the position of
A. Stable equilibrium
B. Unstable equilibrium
C. Neutral equilibrium
D. All of the above
Answer : A

25. A uniform rod 9 m long weighing 40 kg is pivoted at a point 2 m from one end where a weight of 120 kg is suspended. The required force acting at the end in a direction perpendicular to rod to keep it equilibrium, at an inclination 60° with horizontal, is
A. 40 kg
B. 60 kg
C. 10 kg
D. 100 kg
Answer : C

26. To attain the synchronous orbit, the launch of a satellite, is done from a place
A. On equator
B. On 30° latitude
C. On 45° latitude
D. On the poles
Answer : A

27. The pole distance is measured in
A. Distance scale
B. Force scale
C. Mass scale
D. Time scale
Answer : B

28. The following factor affects the orbit of a satellite up to an altitude of 720 km from the earth's surface
A. Uneven distribution of the gravitational field
B. Gravity of the sun and the moon
C. Aerodynamic forces
D. None of these
Answer : D

29. A body of weight w placed on an inclined plane is acted upon by a force P parallel to the plane which causes the body just to move up the plane. If the angle of inclination of the plane is ? and angle of friction is ?, the minimum value of P, is
A. w sin (? - ?)/cos ?
B. w sin (? - ?)/cos ?
C. w cos (? + ?)/cos ?
D. w sin? cos(? - ?)/sin ?
Answer : B

30. Kinetic friction may be defined as
A. Friction force acting when the body is just about to move
B. Friction force acting when the body is in motion
C. Angle between normal reaction and resultant of normal reaction and limiting friction
D. Ratio of limiting friction and normal reaction
Answer : B

31. When a body falls freely under gravitational force, it possesses
A. Maximum weight
B. Minimum weight
C. No weight
D. No effect on its weight
Answer : C

32. A vehicle weighing w kg is to run on a circular curve of radius r. If the height of its centre of gravity above the road level is h and the distance between the centres of wheels is 2a, the maximum velocity, in order to avoid over turning, will be
A. gra/h
B. ?(gra/h)
C. 3?(gra/h)
D. 4?(gra/h)
Answer : B

33. A particle executes a simple harmonic motion. While passing through the mean position, the particle possesses
A. Maximum kinetic energy and minimum potential energy
B. Maximum kinetic energy and maximum potential energy
C. Minimum kinetic energy and maximum potential energy
D. Minimum kinetic, energy and minimum potential energy
Answer : A

34. The vertical reaction at the support A of the structure shown in below figure, is
A. 1 t
B. 2 t
C. 3 t
D. 3.5 t
Answer : C

35. Two forces act an angle of 120°. If the greater force is 50 kg and their resultant is perpendicular to the smaller force, the smaller force is
A. 20 kg
B. 25 kg
C. 30 kg
D. 35 kg
Answer : B

36. When a body in equilibrium undergoes an infinitely small displacement, work imagined to be done, is known as
A. Imaginary work
B. Negative work
C. Virtual work
D. None of these
Answer : C

37. If two forces are in equilibrium, then the forces must (i) Be equal in magnitude (ii) Be opposite in sense (iii) Act along the same line The correct answer is
A. (i) and (ii)
B. (i) and (iii)
C. Only (i)
D. All (i), (ii) and (iii)
Answer : D

38. Joule is the unit of
A. Work
B. Force
C. Power
D. Torque
Answer : A

39. Varingons theorem of moments states
A. Arithmetical sum of the moments of two forces about any point, is equal to the moments of their resultant about that point
B. Algebraic sum of the moments of two forces about any point, is equal to the moment of their resultant about that point
C. Arithmetical sum of the moments of the forces about any point in their plane, is equal to the moment of their resultant about that point
D. Algebraic sum of the moments of the forces about any point in their plane, is equal to the moment of their resultant about that point
Answer : D

40. Pick up he incorrect statement from the following. In case of suspension bridge due to rise in temperature,
A. Dip of the cable increases
B. Length of the cable increases
C. Dip of the cable decreases
D. None of these
Answer : C

41. A square hole is made in a circular lamina, the diagonal of the square is equal to the radius of the circle as shown in below figure the shift in the centre of gravity is
A. r (? - 0.75)/(? - 0.5)
B. r (? - 0.25)/(? - 0.75)
C. r (? - 0.5)/(? - 0.75)
D. r (? - 0.5)/(? - 0.25)
Answer : A

42. The inherent property of a body which offers reluctance to change its state of rest or uniform motion, is
A. Weight
B. Mass
C. Inertia
D. Momentum
Answer : C

43. The reaction at the support D of the continuous beam ABCD, hinged at two points shown in below figure is
A. 1.6 t ?
B. 1.6 t ?
C. 0.5 t ?
D. 0.5 t ?
Answer : B

44. 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

45. The reaction at the support B of the beam shown in below figure is
A. 1.6 t
B. 9.6 t
C. 8.5 t
D. 0.5 t
Answer : C

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

47. A hoop of radius 3 m weighs 100 kg. It rolls along a horizontal floor so that at its centre of mass has a speed of 200 mm/sec. The work required to stop the hoop is
A. 2 J
B. 4 J
C. 6 J
D. 8 J
Answer : B

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

49. The equation of motion of a particle starting from rest along a straight line is x = t³ - 3l² + 5. The ratio of the velocities after 5 sec and 3 sec will be
A. 2
B. 3
C. 4
D. 5
Answer : D

50. Two circular discs of same weight and thickness are made from metals having different densities. Which disc will have the larger rotational inertia about its central axis?
A. Disc with larger density
B. Disc with smaller density
C. Both discs will have same rotational inertia
D. None of the above
Answer : B