McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
| 51. |
Which of the following are important parts of knuckle joint? |
| A. | eye |
| B. | pin |
| C. | fork |
| D. | each of the mentioned |
| Answer» D. each of the mentioned | |
| Explanation: all the mentioned parts are important components of knuckle joint. | |
| 52. |
Calculate the diameter of pin from shear consideration with maximum shear stress allowed is 40NN/mm² and an axial tensile force of 50kN is acting on the rod. |
| A. | 39mm |
| B. | 44mm |
| C. | 49mm |
| D. | 52mm |
| Answer» A. 39mm | |
| Explanation: as the pin is subjected to double shear diameter (d) = √(2p/π x τ) = 38.80mm. | |
| 53. |
A knuckle joint can be used in valve mechanism of a reciprocating engine. |
| A. | yes |
| B. | no |
| C. | yes but there are stress probles |
| D. | no as it is very dangerous to use |
| Answer» A. yes | |
| Explanation: knuckle joint can be used till the rods coincide or intersect in a plane. | |
| 54. |
Cotter joint is used when the members are subjected to which type of stresses? |
| A. | axial tensile |
| B. | axial compressive |
| C. | axial tensile or compressive |
| D. | none of the mentioned |
| Answer» C. axial tensile or compressive | |
| Explanation: cotter joint is used when axial forces are applied. | |
| 55. |
The principle of wedge action is used in cotter joint. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: wedge action imparts tightening to the cotter joint. | |
| 56. |
Which of the following is not a part of cotter joint? |
| A. | socket |
| B. | spigot |
| C. | cotter |
| D. | collar |
| Answer» D. collar | |
| Explanation: there is no point of mentioning collar alone in a cotter joint. it has to be a spigot collar or socket collar. | |
| 57. |
Cold riveting holds the connected parts better than hot riveting. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the compression of connected parts in hot riveting causes friction, which resist sliding of one part with respect to other. this force is greater in hot riveting. | |
| 58. |
67 N/mm².; Spigot dia=65mm; thickness 0f collar=15mm |
| A. | 131mm |
| B. | 139mm |
| C. | 141mm |
| D. | 149mm |
| Answer» A. 131mm | |
| Explanation: compressive stress= p/ [(socket dia-spigot dia)*thickness]. | |
| 59. |
Cotter joint can be used to connect two rods for torque transmission purpose. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: cotter joint is never used to connect two rods for torque transmission purpose. | |
| 60. |
Thickness of plate is required more in welding than in riveting. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: in riveting, cross section is weakened due to the holes and to compensate this, thicker plates are required in riveting. | |
| 61. |
The capacity of welded structures to damp vibrations is quite good. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: capacity of welded joints to damp vibrations is poor. | |
| 62. |
Themit consists of a finely divided mixture of iron oxide and copper. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: thermite is a mixture of iron oxide and copper. | |
| 63. |
Rails in the field are generally welded by using |
| A. | thermit welding |
| B. | gas welding |
| C. | electric arc welding |
| D. | forge welding |
| Answer» A. thermit welding | |
| Explanation: wherever it is uneconomical to carry welding equipments, thermit welding is used. | |
| 64. |
In gas welding which of the following is generally used? |
| A. | oxygen-hydrogen |
| B. | oxygen-acetylene |
| C. | oxygen-hydrogen or oxygen-acetylene |
| D. | none of the mentioned |
| Answer» C. oxygen-hydrogen or oxygen-acetylene | |
| Explanation: intense heat is released i a controlled way and at a moderate temperature. | |
| 65. |
Filler material is used in electric resistance welding. |
| A. | yes |
| B. | no filler material used |
| C. | depends on the type of welding |
| D. | none of the listed |
| Answer» B. no filler material used | |
| Explanation: no filler material is used. only the heat released from resistance of metallic parts to current is used for melting the adjoining parts. | |
| 66. |
Which type of welding is generally used in automobile sector? |
| A. | electric arc welding |
| B. | electric resistance welding |
| C. | gas welding |
| D. | forge welding |
| Answer» B. electric resistance welding | |
| Explanation: electric resistance welding can | |
| 67. |
Hard peening is |
| A. | hammering the weld across the length while the joint is hot |
| B. | hammering the weld along the length while the joint is hot |
| C. | hammering the weld along the length while the joint is cold |
| D. | hammering the weld across the length while the joint is cold |
| Answer» B. hammering the weld along the length while the joint is hot | |
| Explanation: hammering is doe to relieve stresses and inducing compressive stresses to improve the fatigue strength of the joint. | |
| 68. |
A rivet is specified as a 20mm rivet. What does it mean? |
| A. | none of the mentioned |
| B. | shank dia 20mm |
| C. | head dia 20mm |
| D. | both head and shank dia 20mm |
| Answer» B. shank dia 20mm | |
| Explanation: terminology is this way. | |
| 69. |
In hand riveting die is a part of hammer. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: die is a part of hammer in machine riveting. | |
| 70. |
The amount by which the two rods to be joined are drawn together is called as? |
| A. | draw |
| B. | portray |
| C. | lead |
| D. | pitch |
| Answer» A. draw | |
| Explanation: draw measures the amount of distance advancing after which spigot rests on socket. | |
| 71. |
Two steel rods connected by cotter joint are subjected to 50 kN load each. What is the minimum diameter required of the rods? (Given: Yielding Stress= 400N/mm² ; Factor of Safety=6) |
| A. | 31mm |
| B. | 35mm |
| C. | 36mm |
| D. | 40mm |
| Answer» A. 31mm | |
| Explanation: d=√(4p/πσ) where σ= yielding stress/f.s ; d=30.90mm or 31 mm. | |
| 72. |
Among punching and drilling, which is cheaper? |
| A. | punching |
| B. | drilling |
| C. | equally expensive |
| D. | cannot be determined |
| Answer» A. punching | |
| Explanation: drilling has more accuracy and is more expensive. | |
| 73. |
Riveting is not recommended for aluminium alloys. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: aluminium alloys have poor weldability and hence riveting is preferred. | |
| 74. |
In joining steel plate and asbestos, welding is preferred over riveting. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: riveting is preferred in joining heterogeneous materials. | |
| 75. |
Quality checking of riveted joint is much expensive than that of welded joint. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: in welding, inspections like radiographic inspections are quite costly. | |
| 76. |
In which of the following bonding theory, water molecules break down to form H+ and OH- ions? |
| A. | electrostatic bonding theory |
| B. | hot strength theory |
| C. | surface tension theory |
| D. | block and wedge theory |
| Answer» A. electrostatic bonding theory | |
| Explanation: in electrostatic bonding theory, water is mixed in clay and sand grains, these water molecules then break into h+ ions and oh– ions. | |
| 77. |
What does the clay particle absorb in electrostatic bonding theory? |
| A. | complete water |
| B. | h+ ions |
| C. | oh–ions |
| D. | sand grains |
| Answer» C. oh–ions | |
| Explanation: the oh– ions are basically the base ions. the clay particles in electrostatic bonding theory, absorb the oh– ions because of the not satisfied valence bond. | |
| 78. |
For bonding action of clays, what is the amount of water needed? |
| A. | 1.5%-8% |
| B. | 3.5%-11% |
| C. | 4.5%-12% |
| D. | 5.5%-13% |
| Answer» A. 1.5%-8% | |
| Explanation: for the bonding action of the clays, water is needed, which activates the | |
| 79. |
What is the amount of sea coal needed in cast irons for large green casting moulding sands? |
| A. | 10% |
| B. | 15% |
| C. | 20% |
| D. | 25% |
| Answer» A. 10% | |
| Explanation: sea coal otherwise is used in small numbers for binding. sea coal is used for surface appearance improvement. it is used about 10% in cast iron moulding sands for large green casting sands. | |
| 80. |
Pitch maybe used up to what percent? |
| A. | 1% |
| B. | 2% |
| C. | 3% |
| D. | 4% |
| Answer» B. 2% | |
| Explanation: pitch distillation of soft coals plays a vital role in bonding theory. pitch is used for getting a good surface finish on iron casts. these pitches generally are used up to be to 2%. | |
| 81. |
Which of the following increases the dry strength of the sand? |
| A. | iron oxides |
| B. | fuel oils |
| C. | cereals |
| D. | dextrin and molasses |
| Answer» D. dextrin and molasses | |
| Explanation: dextrin and molasses are used for increasing the dry strength of the sand, which add hardness to the mould. | |
| 82. |
Cereals improve flowability and lower collapsibility. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: cereals do not improve flowability, as a matter of fact, it reduces it, and, cereals are not known to reduce or not the collapsibility, in fact it is known to improve it. | |
| 83. |
How much should fuel oil be added to increase the moulding ability of sand? |
| A. | 0.01% – 0.1% |
| B. | 0.02% – 0.2% |
| C. | 0.03% – 0.3% |
| D. | 0.04% – 0.4% |
| Answer» A. 0.01% – 0.1% | |
| Explanation: fuel oils are known to have great properties in them. fuel oils are helpful in adding to the increase of the moulding | |
| 84. |
Which of the following function can the spring perform? |
| A. | store energy |
| B. | absorb shock |
| C. | measure force |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: spring can easily perform all the listed functions. | |
| 85. |
The helix angle is very small about 2⁰. The spring is open coiled spring. |
| A. | yes |
| B. | it is closed coiled spring |
| C. | that small angle isn’t possible |
| D. | none of the listed |
| Answer» B. it is closed coiled spring | |
| Explanation: when the helix angle is small, the plane containing each coil is almost at right angles and hence it is called closed coiled spring. | |
| 86. |
The helical spring ad wire of helical torsion spring, both are subjected to torsional shear stresses. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the wire of helical torsion sprig is subjected to bending stresses. | |
| 87. |
Multi leaf springs are not recommended for automobile and rail road suspensions. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: they are highly used in automobile and rail road suspensions. | |
| 88. |
The spring index is the ratio of wire diameter to mean coil diameter. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: it is the ratio of mean coil diameter to wire diameter. | |
| 89. |
If spring index=2.5, what can be concluded about stresses in the wire? |
| A. | they are high |
| B. | they are negligible |
| C. | they are moderate |
| D. | cannot be determined |
| Answer» A. they are high | |
| Explanation: if indexis <3 then stresses are high due to curvature effect. | |
| 90. |
A spring with index=15 is prone to buckling. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: due to large variation, such a spring is prone to buckling. | |
| 91. |
If number of coils are 8 and wire diameter of spring 3mm, then solid length is given by? |
| A. | none of the listed |
| B. | 27mm |
| C. | 24mm |
| D. | 21mm |
| Answer» C. 24mm | |
| Explanation: solid length=8×3. | |
| 92. |
Compressed length is smaller than the solid length. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: compressed is length of spring under maximum compressive force. there is some gap between the coils under maximum load. | |
| 93. |
Pitch of coil is defined as axial distance in compressed state of the coil. |
| A. | yes |
| B. | it is measured in uncompressed state |
| C. | it is same in uncompressed or compressed state |
| D. | none of the listed |
| Answer» B. it is measured in uncompressed state | |
| Explanation: pitch is measured in uncompressed state. | |
| 94. |
The maximum fluctuation of speed is the |
| A. | difference of minimum fluctuation of speed and the mean speed |
| B. | difference of the maximum and minimum speeds |
| C. | sum of the maximum and minimum speeds |
| D. | variations of speed above and below the mean resisting torque line |
| Answer» B. difference of the maximum and minimum speeds | |
| Explanation: the difference between the maximum and minimum speeds during a cycle is called the maximum fluctuation of speed. | |
| 95. |
In a turning moment diagram, the variations of energy above and below the mean resisting torque line is called |
| A. | fluctuation of energy |
| B. | maximum fluctuation of energy |
| C. | coefficient of fluctuation of energy |
| D. | none of the mentioned |
| Answer» A. fluctuation of energy | |
| Explanation: the fluctuation of energy may be determined by the turning moment diagram for one complete cycle of operation.the variations of energy above and below the mean resisting torque line are called fluctuation of energy. | |
| 96. |
The ratio of the maximum fluctuation of energy to the ……. is called coefficient of fluctuation of energy. |
| A. | minimum fluctuation of energy |
| B. | workdone per cycle |
| C. | maximum fluctuation of energy |
| D. | none of the mentioned |
| Answer» B. workdone per cycle | |
| Explanation: the difference between the maximum and the minimum energies is known as maximum fluctuation of energy. | |
| 97. |
Due to the centrifugal force acting on the rim, the flywheel arms will be subjected to |
| A. | tensile stress |
| B. | compressive stress |
| C. | shear stress |
| D. | none of the mentioned |
| Answer» A. tensile stress | |
| Explanation: the tensile stress in the rim due to the centrifugal force, assuming that the rim is unstrained by the arms, is determined in a similar way as a thin cylinder subjected to internal pressure. | |
| 98. |
The cross-section of the flywheel arms is usually |
| A. | elliptical |
| B. | rectangular |
| C. | i-section |
| D. | l-section |
| Answer» A. elliptical | |
| Explanation: the cross-section of the arms is usually elliptical with major axis as twice the minor axis. | |
| 99. |
In order to find the maximum bending moment on the arms, it is assumed as a |
| A. | simply supported beam carrying a uniformly distributed load over the arm |
| B. | fixed at both ends |
| C. | cantilever beam fixed at the hub and carrying a concentrated load at the free end of the rim |
| D. | none of the mentioned |
| Answer» C. cantilever beam fixed at the hub and carrying a concentrated load at the free end of the rim | |
| Explanation: due to the torque transmitted from the rim to the shaft or from the shaft to the rim, the arms will be subjected to bending, because they are required to carry the full torque load. in order to find out the maximum bending moment on the arms, it may be assumed as a cantilever beam fixed at the hub and carrying a concentrated load at the free end of the rim. | |
| 100. |
The diameter of the hub of the flywheel is usually taken |
| A. | equal to the diameter of the shaft |
| B. | twice the diameter of the shaft |
| C. | three times the diameter of the shaft |
| D. | four times the diameter of the shaft |
| Answer» B. twice the diameter of the shaft | |
| Explanation: the diameter of hub is usually taken as twice the diameter of shaft and length from 2 to 2.5 times the shaft diameter. it is generally taken equal to width of the rim. | |
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