McqMate
1. |
Which of the following is incorrect regarding inertia force? |
A. | imaginary force |
B. | acts upon a rigid body |
C. | brings the body to equilibrium |
D. | same direction as of accelerating force |
Answer» D. same direction as of accelerating force |
2. |
Inertia torque acts in the same direction as the accelerating couple? |
A. | true |
B. | false |
Answer» B. false |
3. |
If a force has a line of action at a distance h from the centre of gravity, then the value of h is given by |
A. | i. α/f |
B. | i. α/m.g |
C. | i/m.k |
D. | m.k/i |
Answer» A. i. α/f |
4. |
D-Alembert’s principle is used for which of the following? |
A. | change static problem into a dynamic problem |
B. | change dynamic problem to static problem |
C. | to calculate moment of inertia of rigid bodies |
D. | to calculate angular momentum of a system of masses |
Answer» B. change dynamic problem to static problem |
5. |
2 D ALEMBERT'S PRINCIPLE - DYNAMIC ANALYSIS IN RECIPROCATING ENGINES |
A. | reversed effective force |
B. | net force |
C. | coriolis force |
D. | resultant force |
Answer» A. reversed effective force |
6. |
A body remains in equilibrium if |
A. | inertia force is applied in the same direction to the resultant force |
B. | inertia force is applied in the direction opposite to the resultant force |
C. | inertia force is applied in the direction perpendicular to the resultant force |
D. | inertia force is applied in the direction parallel to the resultant force |
Answer» B. inertia force is applied in the direction opposite to the resultant force |
7. |
Inertia force and the reversed effective force are the same. |
A. | true |
B. | false |
Answer» A. true |
8. |
In the following picture the G is the center of gravity, the quantity h is known as the “offset”. I is the moment of inertia and k is the radius of gyration. Offset’s value is given by? |
A. | i.α/f |
B. | i.α/m.g |
C. | i/m.k |
D. | m.k/i |
Answer» A. i.α/f |
9. |
Considering a four bar chain with each link having linear and angular acceleration, applying D-Alembert’s principle will never result in which of the following member? |
A. | 2- force member |
B. | 3- force member |
C. | 4 – force member |
D. | non accelerating member |
Answer» A. 2- force member |
10. |
Piston effort acts along the line of stroke. |
A. | true |
B. | false |
Answer» A. true |
11. |
In a horizontal engine, reciprocating parts are accelerated when the piston moves from |
A. | tdc to bdc |
B. | bdc to tdc |
C. | midway to tdc |
D. | bdc to midway |
Answer» A. tdc to bdc |
12. |
In a horizontal engine, reciprocating parts are retarded when the piston moves from |
A. | tdc to bdc |
B. | bdc to tdc |
C. | midway to tdc |
D. | bdc to midway |
Answer» B. bdc to tdc |
13. |
When the piston is accelerated, the piston effort is given by which of the following the equation? |
A. | f(l) – f(i) |
B. | f(l) + f(i) |
C. | f(l) ± f(i) |
D. | f(l) – f(i) + r(f) |
Answer» B. f(l) + f(i) |
14. |
In the presence of frictional resistance, the expression for piston effort is |
A. | f(l) – f(i) |
B. | f(l) + f(i) |
C. | f(l) ± f(i) – r(f) |
D. | f(l) – f(i) + r(f) |
Answer» C. f(l) ± f(i) – r(f) |
15. |
Crank effort is the product of crank pin radius and |
A. | thrust on sides |
B. | crankpin effort |
C. | force acting along connecting rod |
D. | piston effort |
Answer» B. crankpin effort |
16. |
In a horizontal engine, the weight of the reciprocating parts also add/subtract to the piston effort. |
A. | true |
B. | false |
Answer» B. false |
17. |
For the given data of an Internal combustion engine : Mass of parts = 180 kg bore = 175 mm, length of stroke = 200 mm, engine speed = 500 r.p.m., length of connecting rod = 400 mm and crank angle = 60° from T.D.C, find the inertia force. |
A. | 17.56 n |
B. | 19.2 n |
C. | 18.53 n |
D. | 18.00 n |
Answer» C. 18.53 n |
18. |
45 N/mm2. The connecting rod length between centres is 1.2 m and the cylinder bore is 0.5 m. If the engine runs at 250 r.p.m. and if the effect of piston rod diameter is neglected, calculate the net load on piston. |
A. | 88000 n |
B. | 90560 n |
C. | 78036 n |
D. | 88357 n |
Answer» D. 88357 n |
19. |
Multi cylinder engines are usually placed at an equal inclination to each other. |
A. | true |
B. | false |
Answer» A. true |
20. |
For a multicylinder engine, the coefficient of fluctuation of speed would vary with |
A. | number of cylinders |
B. | remains unaffected |
C. | length of connecting rod |
D. | input temperature |
Answer» B. remains unaffected |
21. |
In the turning moment diagram of a multicylinder engine, the work done during exhaust stroke is by |
A. | the gases |
B. | on the gases |
C. | piston wall |
D. | valve |
Answer» B. on the gases |
22. |
For a 4 cylinder engine, when the pressure inside the cylinders exceeds the atmospheric pressure then. |
A. | work is done by the gases |
B. | work is done on the gases |
C. | work is done on the piston wall |
D. | work is done by the piston wall |
Answer» A. work is done by the gases |
23. |
In a punching press, which of the following quantity is constant? |
A. | load |
B. | torque |
C. | angular velocity |
D. | angle of rotation |
Answer» B. torque |
24. |
In a punching press, load is 0 at the time of punching. |
A. | true |
B. | false |
Answer» B. false |
25. |
The maximum shear force required for punching depends on |
A. | sheared area |
B. | length of the plate |
C. | speed of the flywheel |
D. | total load |
Answer» A. sheared area |
26. |
A machine punching 38 mm holes in 32 mm thick plate requires 7 N-m of energy per sq. mm of sheared area, find the maximum shear force required. |
A. | 26.7 kn |
B. | 53.4 kn |
C. | 13.35 kn |
D. | 106.8 kn |
Answer» A. 26.7 kn |
27. |
The relation between stroke punch s and radius of crank r is |
A. | s=r |
B. | s=2r |
C. | s=4r |
D. | s=r/2 |
Answer» B. s=2r |
28. |
If the stroke punch is 100mm, find the radius of the crank in mm. |
A. | 200 |
B. | 100 |
C. | 50 |
D. | 400 |
Answer» C. 50 |
29. |
Energy during actual punching operation is same as the energy supplied by the motor. |
A. | true |
B. | false |
Answer» B. false |
30. |
The balance energy required for punching is supplied by the flywheel by |
A. | increase in its kinetic energy |
B. | decrease in its kinetic energy |
C. | decrease in its potential energy |
D. | by variation of mass |
Answer» B. decrease in its kinetic energy |
31. |
When the length of the connecting rod is unknown then the value (θ2 –θ1)/2π is equal to |
A. | t/s |
B. | t/2s |
C. | t/2r |
D. | t/r |
Answer» B. t/2s |
32. |
The size of a cam depends upon |
A. | base circle |
B. | pitch circle |
C. | prime circle |
D. | pitch curve |
Answer» A. base circle |
33. |
The angle between the direction of the follower motion and a normal to the pitch curve is called |
A. | pitch angle |
B. | prime angle |
C. | base angle |
D. | pressure angle |
Answer» D. pressure angle |
34. |
The cam follower generally used in automobile engines is |
A. | knife edge follower |
B. | flat faced follower |
C. | spherical faced follower |
D. | roller follower |
Answer» C. spherical faced follower |
35. |
The cam follower extensively used in air- craft engines is |
A. | knife edge follower |
B. | flat faced follower |
C. | spherical faced follower |
D. | roller follower |
Answer» D. roller follower |
36. |
In a radial cam, the follower moves |
A. | in a direction perpendicular to the cam axis |
B. | in a direction parallel to the cam axis |
C. | in any direction irrespective of the cam axis |
D. | along the cam axis |
Answer» A. in a direction perpendicular to the cam axis |
37. |
A radial follower is one |
A. | that reciprocates in the guides |
B. | that oscillates |
C. | in which the follower translates along an axis passing through the cam centre of rotation. |
D. | none of the mentioned |
Answer» A. that reciprocates in the guides |
38. |
Ofset is provided to a cam follower mechanism to |
A. | minimise the side thrust |
B. | accelerate |
C. | avoid jerk |
D. | none of the mentioned |
Answer» A. minimise the side thrust |
39. |
For low and moderate speed engines, the cam follower should move with |
A. | uniform velocity |
B. | simple harmonic motion |
C. | uniform acceleration and retardation |
D. | cycloidal motion |
Answer» B. simple harmonic motion |
40. |
For high speed engines, the cam follower should move with |
A. | uniform velocity |
B. | simple harmonic motion |
C. | uniform acceleration and retardation |
D. | cycloidal motion |
Answer» D. cycloidal motion |
41. |
Which of the following displacement diagrams should be chosen for better dynamic performance of a cam-follower mechanism ? |
A. | simple hormonic motion |
B. | parabolic motion |
C. | cycloidal motion |
D. | none of the mentioned |
Answer» C. cycloidal motion |
42. |
The displacement of a flat faced follower when it has contact with the flank of a circular arc cam, is given by |
A. | r(1-cosθ) |
B. | r(1-sinθ) |
C. | (r-r1)(1-cosθ) |
D. | (r-r1)(1-sinθ) |
Answer» C. (r-r1)(1-cosθ) |
43. |
The retardation of a flat faced follower when it has contact at the apex of the nose of a circular arc cam, is given by |
A. | ω2×oq |
B. | ω2×oqsinθ |
C. | ω2×oqcosθ |
D. | ω2×oqtanθ |
Answer» A. ω2×oq |
44. |
Centre of masses of the system lies on the axis of rotation. |
A. | 1, 2, 3 and 4 |
B. | 1, 2, and 3 only |
C. | 2, 3 and 4 only |
D. | 1, 3 and 4 only |
Answer» D. 1, 3 and 4 only |
45. |
Which of the following statements is correct about the balancing of a mechanical system? |
A. | if it is under static balance, then there will be dynamic balance also |
B. | if it is under dynamic balance, then there will be static balance also |
C. | both static as well as dynamic balance have to be achieved separately |
D. | none of the mentioned |
Answer» C. both static as well as dynamic balance have to be achieved separately |
46. |
In a locomotive, the ratio of the connecting rod length to the crank radius is kept very large in order to |
A. | minimize the effect of primary forces |
B. | minimize the effect of secondary forces |
C. | have perfect balancing |
D. | start the locomotive conveniently |
Answer» B. minimize the effect of secondary forces |
47. |
Multi-cylinder engines are desirable because |
A. | only balancing problems are reduced |
B. | only flywheel size is reduced |
C. | both (a) and (b) |
D. | none of the mentioned |
Answer» C. both (a) and (b) |
48. |
Secondary forces in reciprocating mass on engine frame are |
A. | of same frequency as of primary forces |
B. | twice the frequency as of primary forces |
C. | four times the frequency as of primary forces |
D. | none of the mentioned |
Answer» B. twice the frequency as of primary forces |
49. |
Work produced by the 4-stroke engine is less because |
A. | one power stroke per 2 revolutions |
B. | one power stroke per revolution |
C. | one power stroke per 4 revolution |
D. | four power stroke per revolution |
Answer» A. one power stroke per 2 revolutions |
50. |
When the work is done on the gases, which of the following effect is observed on the turning moment diagram? |
A. | formation of negative loop |
B. | formation of positive loop |
C. | formation of an infinite loop |
D. | formation of no loop |
Answer» A. formation of negative loop |
51. |
Compression stroke results in |
A. | formation of negative loop |
B. | formation of positive loop |
C. | formation of an infinite loop |
D. | formation of no loop |
Answer» A. formation of negative loop |
52. |
4 strokes engine have a lower thermal efficiency than 2 stroke engine. |
A. | true |
B. | false |
Answer» B. false |
53. |
3 BALANCING MACHINES-FIELD BALANCING OF DISCS AND ROTORS. |
A. | centripetal forces |
B. | centrifugal forces |
C. | friction forces |
D. | inertia forces |
Answer» D. inertia forces |
54. |
Balancing of single rotating mass by balancing masses in same plane and in different planes cannot take place. |
A. | true |
B. | false |
Answer» B. false |
55. |
Which of the following is true for centrifugal force causing unbalance? |
A. | direction changes with rotation |
B. | magnitude changes with rotation |
C. | direction and magnitude both change with rotation |
D. | direction and magnitude both remain unchanged with rotation |
Answer» A. direction changes with rotation |
56. |
In a revolving rotor, the centrifugal force remains balanced as long as the centre of the mass of the rotor lies |
A. | below the axis of shaft |
B. | on the axis of the shaft |
C. | above the axis of shaft |
D. | away from the axis of shaft |
Answer» B. on the axis of the shaft |
57. |
If the unbalanced system is not set right then. |
A. | static forces develop |
B. | dynamic forces develop |
C. | tangential forces develop |
D. | radial forces develop |
Answer» A. static forces develop |
58. |
What is not the effect of unbalanced forces? |
A. | load on bearings |
B. | dangerous vibrations |
C. | stresses in various members |
D. | violation of conservation of mass principle |
Answer» D. violation of conservation of mass principle |
59. |
The critical speed of a shaft with a disc supported in between is equal to the natural frequency of the system in |
A. | transverse vibrations |
B. | torsional vibrations |
C. | longitudinal vibrations |
D. | none of the mentioned |
Answer» A. transverse vibrations |
60. |
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be |
A. | less than unity |
B. | equal to unity |
C. | greater than unity |
D. | zero |
Answer» C. greater than unity |
61. |
The accelerometer is used as a transducer to measure earthquake in Richter scale. Its design is based on the principle that |
A. | its natural frequency is very low in comparison to the frequency of vibration |
B. | its natural frequency is very high in comparison to the frequency of vibration |
C. | its natural frequency is equal to the frequency of vibration |
D. | measurement of vibratory motion is without any reference point |
Answer» C. its natural frequency is equal to the frequency of vibration |
62. |
Critical speed is expressed as |
A. | rotation of shaft in degrees |
B. | rotation of shaft in radians |
C. | rotation of shaft in minutes |
D. | natural frequency of the shaft |
Answer» D. natural frequency of the shaft |
63. |
The first critical speed of an automobile running on a sinusoidal road is calculated by (modeling it as a single degree of freedom system) |
A. | resonance |
B. | approximation |
C. | superposition |
D. | rayleigh quotient |
Answer» A. resonance |
64. |
The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon = gearth/6) is |
A. | ωn |
B. | 0.408ωn |
C. | 0.204ωn |
D. | 0.167ωn |
Answer» A. ωn |
65. |
6 kN/m and the damping constant of the damper is 400 Ns/m. If the mass is 50 kg, then the damping factor (d ) and damped natural frequency (fn), respectively, are |
A. | 0.471 and 1.19 hz |
B. | 0.471 and 7.48 hz |
C. | 0.666 and 1.35 hz |
D. | 0.666 and 8.50 hz |
Answer» A. 0.471 and 1.19 hz |
66. |
5 m/s. |
A. | 4.19 |
B. | 5 |
C. | 3.49 |
D. | 3.36 |
Answer» C. 3.49 |
67. |
Which of the following expression represent the angular acceleration α of the connecting rod? |
A. | −ω2 . sin θ/n |
B. | −ω2 . cos θ.n |
C. | ω2. cos θ/n |
D. | ω2 . sin θ.n |
Answer» A. −ω2 . sin θ/n |
68. |
While calculating angular acceleration of the connecting rod, sin2(θ) term is neglected. |
A. | true |
B. | false |
Answer» A. true |
69. |
In a slider crank mechanism, the length of the crank and connecting rod are 180 mm and 540 mm respectively. The crank position is 45° from inner dead centre. The crank shaft speed is 450 r.p.m. (clockwise), calculate angular velocity of the connecting rod in rad/s. |
A. | 10.3 |
B. | 11.1 |
C. | 12.2 |
D. | 11.8 |
Answer» B. 11.1 |
70. |
When a body is subjected to transverse vibrations, the stress induced in a body will be |
A. | shear stress |
B. | bending stress |
C. | tensile stress |
D. | compressive stress |
Answer» B. bending stress |
71. |
Longitudinal vibrations are said to occur when the particles of a body moves |
A. | perpendicular to its axis |
B. | parallel to its axis |
C. | in a circle about its axis |
D. | none of the mentioned |
Answer» B. parallel to its axis |
72. |
When a body is subjected to transverse vibrations, the stress induced in a body will be |
A. | shear stress |
B. | tensile stress |
C. | compressive stress |
D. | none of the mentioned |
Answer» B. tensile stress |
73. |
The factor which affects the critical speed of a shaft is |
A. | diameter of the disc |
B. | span of the shaft |
C. | eccentricity |
D. | all of the mentioned |
Answer» D. all of the mentioned |
74. |
The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as |
A. | damping factor |
B. | damping coefficient |
C. | logarithmic decrement |
D. | magnification factor |
Answer» D. magnification factor |
75. |
Which of the following systems produce a vibration in the foundation? |
A. | unbalanced machine |
B. | balanced machine |
C. | coupled machine |
D. | uncoupled machine |
Answer» A. unbalanced machine |
76. |
When a periodic disturbing force is applied to a machine, the force is transmitted to the foundation by the means of spring. |
A. | true |
B. | false |
Answer» A. true |
77. |
Which of the following is a type of transmitted force to the foundation? |
A. | damping force |
B. | undamping force |
C. | tensile force |
D. | torsional force |
Answer» A. damping force |
78. |
If the damper is not provided and the system is in resonance, which of the following is the correct isolation factor? |
A. | 0 |
B. | 1/2 |
C. | 1/4 |
D. | infinity |
Answer» D. infinity |
79. |
If isolation factor is negative, then what is the phase difference between transmitted and disturbing force? |
A. | 180° |
B. | 90° |
C. | 450° |
D. | 360° |
Answer» A. 180° |
80. |
Which of the following is true regarding Ɛ>1? |
A. | transmitted force is greater than applied force |
B. | transmitted force is less than applied force |
C. | spring force is less than applied force |
D. | damping force is less than applied force |
Answer» A. transmitted force is greater than applied force |
81. |
Isolation factor is twice the transmissibility ratio. |
A. | true |
B. | false |
Answer» B. false |
82. |
The height of a Watt’s governor is |
A. | directly proportional to speed |
B. | directly proportional to (speed) |
C. | inversely proportional to speed |
D. | inversely proportional to (speed) |
Answer» D. inversely proportional to (speed) |
83. |
A Watt’s governor can work satisfactorily at speeds from |
A. | 60 to 80 r.p.m |
B. | 80 to 100 r.p.m |
C. | 100 to 200 r.p.m |
D. | 200 to 300 r.p.m |
Answer» C. 100 to 200 r.p.m |
84. |
When the sleeve of a Porter governor moves downwards, the governor speed |
A. | increases |
B. | decreases |
C. | remains unaffected |
D. | first increases and then decreases |
Answer» B. decreases |
85. |
In a Porter governor, the balls are attached to the extension of lower links. |
A. | true |
B. | false |
Answer» A. true |
86. |
A Hartnell governor is a |
A. | dead weight governor |
B. | pendulum type governor |
C. | spring loaded governor |
D. | inertia governor |
Answer» C. spring loaded governor |
87. |
A Watt’s governor is a spring loaded governor. |
A. | true |
B. | false |
Answer» B. false |
88. |
Which of the following is a pendulum type governor? |
A. | watt’s governor |
B. | porter governor |
C. | hartnell governor |
D. | none of the mentioned |
Answer» A. watt’s governor |
89. |
A disc is a spinning with an angular velocity ω rad/s about the axis of spin. The couple applied to the disc causing precession will be |
A. | 1/2 iω2 |
B. | iω2 |
C. | 1/2 iωωp |
D. | iωωp |
Answer» D. iωωp |
90. |
The engine of an aeroplane rotates in clockwise direction when seen from the tail end and the aeroplane takes a turn to the left. The effect of gyroscopic couple on the aeroplane will be |
A. | to dip the nose and tail |
B. | to raise the nose and tail |
C. | to raise the nose and dip of the tail |
D. | to dip the nose and raise the tail |
Answer» C. to raise the nose and dip of the tail |
91. |
The steering of a ship means |
A. | movement of a complete ship up and down in vertical plane about transverse axis |
B. | turning of a complete ship in a curve towards right or left, while it moves forward |
C. | rolling of a complete ship side-ways |
D. | none of the mentioned |
Answer» B. turning of a complete ship in a curve towards right or left, while it moves forward |
92. |
The rolling of a complete ship side-ways is known as pitching of a ship. |
A. | true |
B. | false |
Answer» B. false |
93. |
The rotor of a ship rotates in clockwise direction when viewed from stern and the ship takes a right turn. The effect of gyroscopic couple acting on it will be to raise the stern and lower the bow. |
A. | true |
B. | false |
Answer» A. true |
94. |
The pitching of a ship is assumed to take place with simple harmonic motion. |
A. | true |
B. | false |
Answer» A. true |
95. |
Power is transmitted by an electric motor to a machine by using a belt drive. The tensions on the tight and slack side of the belt are 2200 N and 1000 N respectively and diameter of the pulley is 600 mm. If speed of the motor is 1500 r.p.m, find the power transmitted. |
A. | 46.548 kw |
B. | 56.548 kw |
C. | 66.548 kw |
D. | 76.548 kw |
Answer» B. 56.548 kw |
96. |
6 x 10 = 6 rad/s. |
A. | 2.055 m |
B. | 3.055 m |
C. | 4.055 m |
D. | 5.055 m |
Answer» A. 2.055 m |
97. |
Calculate the work done per minute by a punch tool making 20 working strokes per min when a 30 mm diametre hole is punched in 5 mm thick plate with ultimate shear strength og 450 Mpa in each stroke. |
A. | 10.69 knm |
B. | 20.69 knm |
C. | 30.69 knm |
D. | 40.69 knm |
Answer» A. 10.69 knm |
98. |
In latitude 25.0 S, SA (spin axis) of a FG (free gyro) is in position S40E and horizontal. Find the tilt after 6 hours. |
A. | 61.16 up |
B. | 61.16 down |
C. | 51.15 up |
D. | none of the mentioned |
Answer» A. 61.16 up |
99. |
The steering of a ship means |
A. | movement of a complete ship up and down in vertical plane about transverse axis |
B. | turning of a complete ship in a curve towards right r left, while it moves forward |
C. | rolling of a complete ship sideways |
D. | none of the mentioned |
Answer» B. turning of a complete ship in a curve towards right r left, while it moves forward |
100. |
When the pitching of a ship is upward, the effect of gyroscopic couple acting on it will be |
A. | to move the ship towards starboard |
B. | to move the ship towards port side |
C. | to raise the bow and lower the stern |
D. | to raise the stern and lower the bow |
Answer» A. to move the ship towards starboard |
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