| 1. | Stressed parts are always kept in tension. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: cast iron has more compressive strength. | |
| 2. | Which process allows controlling grain structure of the product? |
| A. | casting |
| B. | forging |
| C. | none of the mentioned |
| D. | die casting |
| Answer» B. forging | |
| Explanation: in casting metal is in fluid state and hence impossible to control the grain structure. | |
| 3. | Cast surfaces have good finishing. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: cavity is surrounded by sand and hence not good finish is obtained. | |
| 4. | In forging, metal is in which of the following stage? |
| A. | elastic |
| B. | plastic |
| C. | can be in any stage |
| D. | rigid |
| Answer» B. plastic | |
| Explanation: forging is the working of metal in plastic range. | |
| 5. | Among casting, forging and forging which has the slowest rate of production? |
| A. | casting |
| B. | forging |
| C. | machining |
| D. | all have equal rate of production |
| Answer» C. machining | |
| Explanation: machining each part is very time consuming. | |
| 6. | In manual assembly, cost of screw is higher than the cost of driving a screw. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: generally manufacturing screw is cheaper than driving it. | |
| 7. | Maximum carbon content in welding is usually limited to |
| A. | 0.22% |
| B. | 0.8% |
| C. | 1.5% |
| D. | 2% |
| Answer» A. 0.22% | |
| Explanation: with increase of carbon, welding becomes difficult as weld becomes susceptible to cracks. | |
| 8. | Why tolerances are given to the parts? |
| A. | because it’s impossible to make perfect settings |
| B. | to reduce weight of the component |
| C. | to reduce cost of the assembly |
| D. | to reduce amount of material used |
| Answer» A. because it’s impossible to make perfect settings | |
| Explanation: tolerances are provided to the parts because variations in the material properties introduce errors and production machines themselves have inherent inaccuracies. another reason to introduce tolerance is that it is not possible to make perfect settings by operator so some tolerances are provided. | |
| 9. | What is bilateral tolerance? |
| A. | total tolerance is in 1 direction only |
| B. | total tolerance is in both the directions |
| C. | may or may not be in one direction |
| D. | tolerance provided all over the component body |
| Answer» B. total tolerance is in both the directions | |
| Explanation: total tolerance is specified on both the sides of the basic dimension. this usually have + and – tolerance of equal amount. | |
| 10. | What is mean clearance? |
| A. | maximum size of hole minus maximum size of shaft |
| B. | minimum size of hole minus minimum size of shaft |
| C. | mean size of hole minus mean size of shaft |
| D. | average of both size of shaft and hole |
| Answer» C. mean size of hole minus mean size of shaft | |
| Explanation: statistical approach allows wider tolerances compared to complete interchangeability approach. methods used by statistical approach are usually permits cheaper production. mean clearance is equal to (mean size of hole – mean size of shaft). | |
| 11. | Which of the following is incorrect about tolerances? |
| A. | too loose tolerance results in less cost |
| B. | tolerance is a compromise between accuracy and ability |
| C. | too tight tolerance may result in excessive cost |
| D. | fit between mating components is decided by functional requirements |
| Answer» A. too loose tolerance results in less cost | |
| Explanation: loose tolerance results in increase in cost, assembly problems and poor performance of the product. tight tolerance results in unnecessary machining and inspection time. | |
| 12. | Quality control charts doesn’t depend on which factor? |
| A. | normal distribution |
| B. | random sampling |
| C. | independence between samples |
| D. | binomial distribution |
| Answer» D. binomial distribution | |
| Explanation: in establishing of realistic specifications, control charts are considered as a good guide for the design office. quality | |
| 13. | If a clearance fit is present between shaft and hole, what is the tolerance on shaft or hole for a complete interchangeable approach? |
| A. | ½ of maximum clearance – ½ of minimum clearance |
| B. | ¼ of maximum clearance – ¼ of minimum clearance |
| C. | maximum clearance – minimum clearance |
| D. | ¾ of maximum clearance – ¾ of minimum clearance |
| Answer» A. ½ of maximum clearance – ½ of minimum clearance | |
| Explanation: there are two approaches for deciding of tolerances and shafts i.e. statistical and complete interchangeable approach. there is no risk is taken about a single non-conforming assembly in complete interchangeable approach. | |
| 14. | A beam is said to be of uniform strength, if |
| A. | b.m. is same throughout the beam |
| B. | shear stress is the same through the beam |
| C. | deflection is the same throughout the beam |
| D. | bending stress is the same at every section along its longitudinal axis |
| Answer» D. bending stress is the same at every section along its longitudinal axis | |
| Explanation: beam is said to be uniform strength if at every section along its longitudinal axis, the bending stress is same. | |
| 15. | Stress in a beam due to simple bending is |
| A. | directly proportional |
| B. | inversely proportional |
| C. | curvilinearly related |
| D. | none of the mentioned |
| Answer» A. directly proportional | |
| Explanation: the stress is directly proportional to the load and here the load is in terms of bending. so the stress is directly proportional to bending. | |
| 16. | Which stress comes when there is an eccentric load applied? |
| A. | shear stress |
| B. | bending stress |
| C. | tensile stress |
| D. | thermal stress |
| Answer» B. bending stress | |
| Explanation: when there is an eccentric load it means that the load is at some distance | |
| 17. | On bending of a beam, which is the layer which is neither elongated nor shortened? |
| A. | axis of load |
| B. | neutral axis |
| C. | center of gravity |
| D. | none of the mentioned |
| Answer» B. neutral axis | |
| Explanation: when a beam is in bending the layer in the direction of bending will be in compression and the other will be in tension. one side of the neutral axis will be shortened and the other will be elongated. | |
| 18. | The bending stress is |
| A. | directly proportional to the distance of layer from the neutral layer |
| B. | inversely proportional to the distance of layer from the neutral layer |
| C. | directly proportional to the neutral layer |
| D. | does not depend on the distance of layer from the neutral layer |
| Answer» A. directly proportional to the distance of layer from the neutral layer | |
| Explanation: from the bending equation m/i | |
| 19. | Consider a 250mmx15mmx10mm steel bar which is free to expand is heated from 15C to 40C. what will be developed? |
| A. | compressive stress |
| B. | tensile stress |
| C. | shear stress |
| D. | no stress |
| Answer» D. no stress | |
| Explanation: if we resist to expand then only stress will develop. here the bar is free to expand so there will be no stress. | |
| 20. | The safe stress for a hollow steel column which carries an axial load of 2100 kN is 125 MN/m2. if the external diameter of the column is 30cm, what will be the internal diameter? |
| A. | 25 cm |
| B. | 26.19cm |
| C. | 30.14 cm |
| D. | 27.9 cm |
| Answer» B. 26.19cm | |
| Explanation: area of the cross section of column = π/4 (0.302 – d2) m2 | |
| 21. | Stress intensity factor is the critical value of stress at which crack extension occurs. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: stress intensity specifies the stress intensity at the tip of the crack. | |
| 22. | Fracture toughness does not depend upon geometry of the part containing crack |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: fracture toughness is directly proportional to a factor y that depends upon geometry of the part having crack. | |
| 23. | How many modes are there for crack propagation? |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 5 |
| Answer» B. 3 | |
| Explanation: opening, sliding and tearing are the 3 modes. | |
| 24. | A curved beam has neutral axis is curved while loaded and straight when unloaded. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: curved beam’s neutral axis is always curved irrespective of the loading. | |
| 26. | 1816mm and radius of centroidal axis is 100mm, then find the bending stress at inner fibre whose radius is 50mm. Area of cross section of beam is 7200mm² and the beam is loaded with 100kN of load. |
| A. | 97.3 |
| B. | 95.8 |
| C. | 100.6 |
| D. | none of the mentioned |
| Answer» C. 100.6 | |
| Explanation: e=100-89.816=10.8184mm, h=89.1816-50=39.1816mm, m=100 x 100 n- | |
| 27. | 1816/ [7200 x 10.8184 x 50] or σ=100.6N/mm². |
| A. | 14.80mm |
| B. | 13.95mm |
| C. | 16.5mm |
| D. | 17.2mm |
| Answer» B. 13.95mm | |
| Explanation: σ(b)=mh/ aer or σ(b)=1000x4dx(4d-0.2d-3.5d)/ 0.8d²x0.02dx3.5d , σ(b)=21428.6/d² | |
| 28. | A curved beam with eccentricity 0.02D is loaded with 1kN.Centroidal radius=4D and inner and outer radii are 3.5D and 4.5D respectively. Area of cross section is 0.8D². Find the dimension D if allowable stress is 110N/mm² and considering only direct tensile stress. |
| A. | 4.7mm |
| B. | 6.8mm |
| C. | 13.95mm |
| D. | 3.4mm |
| Answer» D. 3.4mm | |
| Explanation: direct tensile stress=1000/0.8d² or σ (t) =1250/d² 1250/d²=110 or d=3.4mm. | |
| 29. | All type of stresses vanishes after as soon as the applied load is removed. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: residual stresses are independent of the load. | |
| 30. | Residual stresses are always added in the load stresses and hence are always harmful. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: residual stresses may be beneficial when they are opposite to load stresses and hence are subtracted from load stresses. | |
| 31. | Which of the following is the numerator of factor safety formula? |
| A. | working stress |
| B. | shear stress |
| C. | tensile stress |
| D. | ultimate stress |
| Answer» D. ultimate stress | |
| Explanation: factor of safety is defined as ratio of ultimate stress and working stress. it is also called as factor of ignorance. the factor of safety is dependent on the type of load. | |
| 32. | Which of the following can be the factor of safety for shock loading? |
| A. | 11 |
| B. | 13 |
| C. | 4 |
| D. | 7 |
| Answer» B. 13 | |
| Explanation: for shock loading, the range in which the factor of safety can lie is 12 to 15. therefore only 13 lies in that range and 11, 4, 7 are all values which are beyond that range. | |
| 33. | Factor of safety is used to find out the reliability of the design. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: factor of safety tells us about how much load the material can take before it fails. basically, it states the load carrying capacity of a material beyond the actual load. | |
| 34. | What can understand by the factor of safety equal to one? |
| A. | it means that the structure will fail under load |
| B. | it means that the structure will only support the actual load |
| C. | it means that the structure will support more than the actual load |
| D. | there is no relation between factor safety and load application |
| Answer» B. it means that the structure will only support the actual load | |
| Explanation: when the factor of safety is one it means that the ultimate stress is equal to the working stress and therefore the body can only support load up to actual load and no more before failing. | |
| 35. | For which of the following design factor of |
| A. | 0.1 |
| B. | 1 |
| C. | 2 |
| D. | 0.9 |
| Answer» C. 2 | |
| Explanation: if the design factor of safety is not more than 1 then the design may not work and will fail under certain conditions. | |
| 36. | What is a safe factor of failure for a component which on failure can result in financial loss or serious injury? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» D. 4 | |
| Explanation: for components which on failing can be hazardous and can lead to serious injuries, death and financial loss, the factor of safety should be taken equal to or more than 4. | |
| 37. | Design factor for most aircraft structures is 2. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the design factor of safety for most aircraft structures or components is taken to be 1.5 and not 2. more factors affect this value, but it is most of the time taken as 1.5. | |
| 38. | Does ASME Standard take into consideration shock and fatigue factors? |
| A. | yes |
| B. | no |
| Answer» A. yes | |
| Explanation: moment is multiplied by a number to consider these factors while designing the shaft. | |
| 39. | Calculate the tension in the rope of pulley C. “The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm” |
| A. | 6778.3n and 7765.3n |
| B. | 5948.15n and 2288.75n |
| C. | 5468.4n ad 8678.3n |
| D. | none of the listed |
| Answer» B. 5948.15n and 2288.75n | |
| Explanation: (p₃-p₄)x150=549.3×1000 and p₃/p₄=2.6. hence p₃=5948.15n and p₄=2288.75n. | |
| 40. | If bending moment on point B in horizontal plate is M and in vertical plane is m, then the net bending moment at point B is? “The layout of a shaft supported on bearings at A & B is shown. Power is supplied by means of a vertical belt on pulley B which is then transmitted to pulley C carrying a horizontal belt. The angle of wrap is 180’ and coefficient of friction is 0.3. Maximum permissible tension in the rope is 3kN. The radius of pulley at B & C is 300mm and 150mm” |
| A. | m |
| B. | m |
| C. | m+m |
| D. | √m²+m² |
| Answer» D. √m²+m² | |
| Explanation: the two moments act perpendicularly to each other. | |
| 41. | If yielding strength=400N/mm², the find the permissible shear stress according to ASME standards. |
| A. | 72 n/mm² |
| B. | 76 n/mm² |
| C. | 268 n/mm² |
| D. | 422 n/mm² |
| Answer» A. 72 n/mm² | |
| Explanation: 0.18×400. | |
| 42. | The strength of hollow shaft is more than the strength of solid shaft of same weight. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: outer fibers are more effective in resisting the applied moments. in hollow shafts material is removed and spread on a larger radius. | |
| 43. | Solid shafts are used in epicyclic gearboxes. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: in epicyclic gears, one shaft rotates inside other and hence hollow shafts are used. | |
| 44. | Refer to fig Two plates are fastened by means of two bolts. The yield strength of bolt is 400N/mm² and factor of safety is 4. Determine the size of the bolts. |
| A. | 8mm |
| B. | 9mm |
| C. | 10mm |
| D. | 11mm |
| Answer» A. 8mm | |
| Explanation: permissible hear stress=0.5 x 400 /4 =50n/mm². p=2 (π xd²/4) x τ or 5000=2 x π x d² x 50/4 or d=7.97mm. | |
| 45. | 8’CW from the vertical. Hence net shear force = √ [5000cos36.8+1250]²+ [5000sin36.8]². |
| A. | 10.74mm |
| B. | 9.23mm |
| C. | 11.54mm |
| D. | 8.68mm |
| Answer» A. 10.74mm | |
| Explanation: the maximum shear force to which any bolt is subjected is 6047.44n. hence 0.5 x 400/3= 4 x 6047.44/πd² or d=10.74mm. | |
| 46. | Which bolt is under maximum shear stress? |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | all are under equivalent shear stress |
| Answer» C. 3 | |
| Explanation: primary shear force acts equally on the three bolts in the vertically upward direction while the moment is cw along cg so its effect on bolts will be acw. hence secondary shear force acts vertically upward on bolt 3 and vertically downward on bolt 1. | |
| 47. | Arrange the bolts in order of decreasing shear stresses. |
| A. | 1>2>3 |
| B. | 2>1>3 |
| C. | 3>1>2 |
| D. | 3>2>1 |
| Answer» D. 3>2>1 | |
| Explanation: on bolt 3,primary and secondary shear stress act in same direction, on bolt 2 there is no secondary shear stress and on bolt 1 the two act in opposite direction. | |
| 48. | Determine the size of the bolts if yield strength of bolt is 400N/mm² and factor of safety is 4. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel. |
| A. | 14.34mm |
| B. | 13.44mm |
| C. | 15.44mm |
| D. | 12.66mm |
| Answer» B. 13.44mm | |
| Explanation: clearly bolt 3 is under maximum shear stress. net shear stress= primary shear stress + secondary shear stress or τ= (1000+6100) n or 0.5 x 400//4=7100 x | |
| 49. | A knuckle joint is unsuitable for two rotating shafts, which transmit torque |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: knuckle joint can’t be used for torque transmission. | |
| 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. | |
| 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. | |
| 101. | The gears on camshaft and crankshaft are known as | |
| A. | lining gears | |
| B. | aligning gears | |
| C. | timing gears | |
| D. | tuning gears | |
| Answer» C. timing gears | ||
| Explanation: these gears are called timing gears. | ||
| 102. | The material known as high carbon high copper chrome silicon cast steel is used for making |
| A. | camshaft |
| B. | cylinder body |
| C. | cylinder head |
| D. | piston |
| Answer» A. camshaft | |
| Explanation: material used for making camshafts is high carbon high copper chrome silicon cast steel. | |
| 103. | Camshaft gear is made from which material |
| A. | cast iron |
| B. | mild steel |
| C. | bakelite |
| D. | brass |
| Answer» C. bakelite | |
| Explanation: camshaft gears are made from bakelite. | |
| 104. | The main reasons for crankshaft wear are |
| A. | different loads at some points of rotation |
| B. | centrifugal forces due to crankshaft rotation |
| C. | misalignment in connecting rod |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: all the three are the reasons for crankshaft wear. | |
| 105. | The main causes of crankshaft vibration are |
| A. | variation in torque |
| B. | cyclic variation of gas and combustion products |
| C. | unbalanced weight of parts |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: crankshaft vibration is caused by all the above mentioned causes. | |
| 106. | In the cam, the distance between the base circle and the nose is called |
| A. | lift |
| B. | lobe |
| C. | flank |
| D. | pitch |
| Answer» A. lift | |
| Explanation: distance between the base circle and nose is called lift of cam. | |
| 107. | The crankshaft rotates the camshaft using |
| A. | belt drive |
| B. | chain drive |
| C. | gear drive |
| D. | motor drive |
| Answer» B. chain drive | |
| Explanation: chain drive is used to connect | |
| 108. | The crankshaft should be inspected for |
| A. | cracks |
| B. | alignment of crankpins and journals |
| C. | cleanliness of oil gallaries |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: crankshaft should be inspected for all the above mentioned faults. | |
| 109. | A radial bearing supports the load that acts along the axis of the shaft. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: radial bearing supports the load acting perpendicular to the axis of the shaft. | |
| 110. | Sliding contact bearings, also called plain bearings have no problem of wear. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: surface of shaft slide over surface of the bush resulting in friction and wear. | |
| 111. | Which of the following are true about plasticity? |
| A. | permanent deformation |
| B. | ability to retain deformation under load or after removal of load |
| C. | plastic deformation is greater than elastic deformation |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: this is the basic definition of plasticity. | |
| 112. | Modulus of resilience is defined as |
| A. | strain energy per unit volume |
| B. | strain energy per unit area |
| C. | independent of strain energy |
| D. | none of the mentioned |
| Answer» A. strain energy per unit volume | |
| Explanation: modulus of resilience is strain energy per unit volume. | |
| 113. | In gear boxes and small size motors, rolling contact bearings are used. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: in small size applications, rolling contact bearings are preferred. | |
| 114. | There is problem of alignment in deep groove ball bearings. |
| A. | yes |
| B. | no, it is self-aligning |
| C. | it aligns itself only in some particular cases |
| D. | can’t be determined |
| Answer» A. yes | |
| Explanation: it is not self-aligning. | |
| 115. | Deep groove ball bearing has immense rigidity. |
| A. | true |
| B. | no it has point contact and hence low rigidity |
| C. | it has surface contact |
| D. | it has line contact |
| Answer» B. no it has point contact and hence low rigidity | |
| Explanation: due to point contact, rigidity is not so good. | |
| 116. | Cylindrical load bearing has lower load capacity as compared to deep groove ball bearing. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: cylindrical load bearing has a line contact and hence higher load capacity. | |
| 117. | Angular contact bearing can take thrust as well as radial loads. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: the line of reaction at the contact surfaces makes an angle with axis of bearing and thus has two components, hence allowing it to take both type of loads. | |
| 118. | The angular play bearing must be mounted without axial play. |
| A. | yes |
| B. | little tolerance is adjusted |
| C. | little tolerance is necessary |
| D. | can’t be stated |
| Answer» A. yes | |
| Explanation: there is no tolerance of misalignment. | |
| 119. | Taper rolling supports |
| A. | axial loads |
| B. | thrust loads |
| C. | both axial and thrust loads |
| D. | none of the mentioned |
| Answer» C. both axial and thrust loads | |
| Explanation: the line of reaction makes an angle with the axis of bearing and hence both type of loads can be carried. | |
| 120. | Which of the following cannot tolerate misalignment? |
| A. | angular contact bearing |
| B. | cylinder roller bearing |
| C. | thrust ball bearings |
| D. | all of the listed |
| Answer» D. all of the listed | |
| Explanation: all of these require précised alignment. | |
| 121. | Cylinder roller creates lesser noise than deep groove ball bearing. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: due to line contact, cylinder roller creates far more noise. | |
| 122. | Straight bevel gears are easy to design and manufacture and give reasonably good service with quieter operation. |
| A. | true |
| B. | no, noise problem |
| C. | no, vibration problem |
| D. | none of the listed |
| Answer» B. no, noise problem | |
| Explanation: they produce a lot of noise while working. | |
| 123. | Which of the following creates smoother motion? |
| A. | straight bevel gears |
| B. | spiral bevel gears |
| C. | equal for straight and spiral |
| D. | none of the mentioned |
| Answer» B. spiral bevel gears | |
| Explanation: spiral bevel gear has smooth engagement which results in quieter operation. | |
| 124. | When the pitch angle is greater than 90⁰, it is called external bevel gear. |
| A. | true |
| B. | internal |
| C. | helical |
| D. | herringbone |
| Answer» B. internal | |
| Explanation: for external bevel gear, pitch angle is less than 90⁰. | |
| 126. | Crown gears having a pitch angle of 90⁰ |
| A. | =90 |
| B. | <90 |
| C. | >90 |
| D. | none of the listed |
| Answer» C. >90 | |
| Explanation: application of crown gear according to its structure. | |
| 127. | Which of the following are characteristics of skew bevel gears? |
| A. | straight teeth |
| B. | mounted on parallel shafts |
| C. | mounted on intersecting shafts |
| D. | all of the mentioned |
| Answer» A. straight teeth | |
| Explanation: they are used in non-parallel and non-intersecting shafts. | |
| 128. | Hypoid gears are based on surfaces that are paraboloids of revolution. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: they are hyperboloids of revolution. | |
| 129. | When two hyperboloids are rotated, the resulting motion is |
| A. | sliding |
| B. | turning |
| C. | combination of turning and sliding |
| D. | rotary |
| Answer» C. combination of turning and sliding | |
| Explanation: there is turning as well as sliding motion. | |
| 130. | Zerol gears are straight bevel gears with zero spiral angle. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: they happen to fall in the category of spiral bevel gears. | |
| 131. | Zerol gears give lesser contact ratio. |
| A. | true |
| B. | no, larger contact ratio |
| C. | zero contact |
| D. | none of the listed |
| Answer» B. no, larger contact ratio | |
| Explanation: zerol gears have more gradual contact and slighter larger contact ratio. | |
| 132. | Hydrodynamic lubrication takes place in region? |
| A. | bc |
| B. | cd |
| C. | both bc and cd |
| D. | none of the mentioned |
| Answer» B. cd | |
| Explanation: in cd thick film of lubrication has developed. | |
| 133. | Coefficient of friction is minimum at |
| A. | it is same at each point |
| B. | b |
| C. | c |
| D. | d |
| Answer» C. c | |
| Explanation: it is minimum at the transition zone. | |
| 134. | Bearing modulus is the bearing characteristic number at |
| A. | b |
| B. | c |
| C. | d |
| D. | none of the listed |
| Answer» B. c | |
| Explanation: bcn modulus is the the bcn number corresponding to the minimum coefficient of friction. | |
| 135. | If viscosity of the lubricant is very low than BCN will lie in the region |
| A. | bc |
| B. | point c |
| C. | cd |
| D. | can’t be determined |
| Answer» A. bc | |
| Explanation: due to low viscosity, lubricant will not separate the two surfaces resulting in partial contact. | |
| 136. | The fundamental equation for viscous flow is given by ∆pbhᵌ/6µl where symbols have their usual meanings. |
| A. | 6 is to be replaced by 3 |
| B. | 6 is to be replaced by 12 |
| C. | 6 is to be replaced by 9 |
| D. | 6 is to be replaced by 15 |
| Answer» B. 6 is to be replaced by 12 | |
| Explanation: it is givenby ∆pbhᵌ/12µl. | |
| 137. | A single transverse weld is preferred over |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: a single transverse weld is not preferred because the edge of the plate which is not welded can warp out of shape. | |
| 138. | Transverse fillet weld can be designed using the same equations as of parallel fillet weld. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: vice versa is true as strength of transverse fillet weld is greater than that of parallel fillet weld. | |
| 139. | Which of the following are functions of bearings? |
| A. | ensure free rotation of shaft with minimum friction |
| B. | holding shaft in a correct position |
| C. | transmit the force of the shaft to the frame |
| D. | all of the listed |
| Answer» D. all of the listed | |
| Explanation: bearings are used for all the above listed purposes. | |
| 140. | Which of the following is measure of stiffness? |
| A. | modulus of elasticity |
| B. | modulus of plasticity |
| C. | resilience |
| D. | toughness |
| Answer» A. modulus of elasticity | |
| Explanation: stiffness is the ability of material to resist deformation under external load. hence it is measured by modulus of elasticity. | |
| 141. | Which of the following facts are true for resilience? |
| A. | ability of material to absorb energy when deformed elastically |
| B. | ability to retain deformation under the application of load or after removal of load |
| C. | ability of material to absorb energy when deformed plastically |
| D. | none of the mentioned |
| Answer» A. ability of material to absorb energy when deformed elastically | |
| Explanation: toughness is ability to store energy till proportional limit during deformation and to release this energy when unloaded. | |
| 142. | Shot blasting process improves the endurance limit of the component. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 143. | While designing a forging, the profile is selected such that the fibrous lines are parallel to the tensile forces and perpendicular to shear forces. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 144. | What is the expression of the bending equation? |
| A. | m/i = σ/y = e/r |
| B. | m/r = σ/y = e/i |
| C. | m/y = σ/r = e/i |
| D. | m/i = σ/r = e/y |
| Answer» A. m/i = σ/y = e/r | |
| 145. | The bending stress is |
| A. | directly proportional to the distance of layer from the neutral layer |
| B. | inversely proportional to the distance of layer from the neutral layer |
| C. | directly proportional to the neutral layer |
| D. | does not depend on the distance of layer from the neutral layer |
| Answer» A. directly proportional to the distance of layer from the neutral layer | |
| 146. | The critical value at which crack extension occurs is called |
| A. | stress intensity factor |
| B. | toughness |
| C. | fracture toughness |
| D. | none of the mentioned |
| Answer» C. fracture toughness | |
| 147. | If for a curved beam of trapezoidal cross section, radius of neutral axis is 89.1816mm and radius of centroidal axis is 100mm, then find the bending stress at inner fibre whose radius is 50mm. Area of cross section of beam is 7200mm² and the beam is loaded with 100kN of load. |
| A. | 97.3 |
| B. | 95.8 |
| C. | 100.6 |
| D. | none of the mentioned |
| Answer» C. 100.6 | |
| 148. | Which of the following can be the factor of safety for a dead load? |
| A. | 6 |
| B. | 2 |
| C. | 4 |
| D. | 7 |
| Answer» C. 4 | |
| 149. | For which of the following design factor of safety the design will work properly? |
| A. | 0.1 |
| B. | 1 |
| C. | 2 |
| D. | 0.9 |
| Answer» C. 2 | |
| 151. | If allowable shear stress in the shaft is 70N/mm² and torsional and bending moments are M=1185000N-mm and m=330000N-mm, find the diameter of the shaft. | |
| A. | 36.8mm | |
| B. | 39.7mm | |
| C. | 44.7mm | |
| D. | 40.3mm | |
| Answer» C. 44.7mm | ||
| 152. | Calculate the shaft diameter on rigidity basis if torsional moment is 196000N-mm, length of shaft is 1000mm. Permissible angle of twist per meter is 0.5’ and take G=79300N/mm². |
| A. | none of the listed |
| B. | 41.2mm |
| C. | 35.8mm |
| D. | 38.8mm |
| Answer» B. 41.2mm | |
| 153. | The stiffness of solid shaft is more than the stiffness of hollow shaft with same weight. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 154. | Solid shaft is costlier than hollow shaft of same weight. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 155. | Flexible shafts have rigidity in torsion making them flexible. |
| A. | low |
| B. | high |
| C. | very high |
| D. | infinitely small |
| Answer» B. high | |
| 156. | Flexible shafts have rigidity in bending moment. |
| A. | high |
| B. | low |
| C. | very high |
| D. | extremely low |
| Answer» B. low | |
| 157. | A force 2P is acting on the double transverse fillet weld. Leg of weld is h and length l. Determine the shear stress in a plane inclined at θ with horizontal. |
| A. | psinθ(sinθ+cosθ)/hl |
| B. | p(sinθ+cosθ)/hl |
| C. | pcosθ(sinθ+cosθ)/hl |
| D. | none of the listed |
| Answer» A. psinθ(sinθ+cosθ)/hl | |
| 158. | Maximum shear stress in transverse fillet weld of leg h and length l is |
| A. | p/hl |
| B. | 1.21p/hl |
| C. | p/1.21hl |
| D. | none of the listed |
| Answer» B. 1.21p/hl | |
| 159. | Hollow saddle key is superior to flat saddle key as far as power transmitting capability is concerned. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 160. | Saddle key is more suitable than sunk key for heavy duty applications. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 161. | The main advantage of sunk key is that it is a drive. |
| A. | positive |
| B. | negative |
| C. | neutral |
| D. | none of the listed |
| Answer» A. positive | |
| 162. | Woodruff key permits movement b/w shaft and the hub. |
| A. | axial |
| B. | radial |
| C. | eccentric |
| D. | none of the listed |
| Answer» B. radial | |
| 163. | Determine the length of kennedy key required to transmit 1200N-m and allowable shear in the key is 40N/mm². The diameter of shaft and width of key can be taken as 40mm and 10mm respectively. |
| A. | 49mm |
| B. | 36mm |
| C. | 46mm |
| D. | 53mm |
| Answer» D. 53mm | |
| 164. | Splines are keys. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 165. | Refer to fig. Two plates are fastened by means of two bolts. The yield strength of bolt is 400N/mm² and factor of safety is 4. Determine the permissible shear stress in the bolts. |
| A. | 100n/mm² |
| B. | 50n/mm² |
| C. | 25n/mm² |
| D. | 75n/mm² |
| Answer» B. 50n/mm² | |
| 166. | Determine the secondary shear stress acting on the bolt 3 and its direction. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm.Also P=5kN acts at a distance of 200mm from the channel. |
| A. | 6100n vertically up |
| B. | 4500n vertically down |
| C. | 6100n vertically up |
| D. | 4500n vertically down |
| Answer» C. 6100n vertically up | |
| 167. | Determine the size of the bolts if yield strength of bolt is 400N/mm² and factor of safety is 4. The bolts are equidistant having separated by 60mm and the margin to the left and right is 25mm. Also P=5kN acts at a distance of 200mm from the channel. |
| A. | 14.34mm |
| B. | 13.44mm |
| C. | 15.44mm |
| D. | 12.66mm |
| Answer» B. 13.44mm | |
| 168. | Knuckle Joint can’t be used to connect two intersecting rods. |
| A. | yes |
| B. | no, it can’t be used |
| C. | it can be used with some modificatios |
| D. | it is expensive and hence isn’t used |
| Answer» B. no, it can’t be used | |
| 169. | A knuckle joint is also called socket pin joint. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 170. | If knuckle joint is to fail by crushing failure of pin in fork, then determine the diameter of knuckle pin when 50kN axial tensile force act on rods. Given: Max allowable compressive stress=25N/mm², thickness of each eye of fork=25mm. |
| A. | 40mm |
| B. | 50mm |
| C. | 60mm |
| D. | 70mm |
| Answer» A. 40mm | |
| 171. | Can the cotter joint be used to connect slide spindle and fork of valve mechanism? |
| A. | true |
| B. | false |
| Answer» A. true | |
| 172. | Among gas and electric arc welding, which has the higher rate of heating? |
| A. | gas welding |
| B. | electric arc welding |
| C. | gas welding and electric arc welding have equal rate of heating |
| D. | cannot be determined |
| Answer» B. electric arc welding | |
| 173. | Forge welding involves heating of parts to elastic stage and joint is prepared by impact force. |
| A. | yes |
| B. | no, it is done up to plastic stage |
| C. | heating is done up to boiling point |
| D. | none of the listed |
| Answer» B. no, it is done up to plastic stage | |
| 174. | Which of the following isn’t a main part of rivet? |
| A. | head |
| B. | shank |
| C. | point |
| D. | thread |
| Answer» D. thread | |
| 176. | Among punching and drilling, punching is safer. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 177. | What is the amount of sea coal needed in cast irons for small casting moulding sands? |
| A. | 1% |
| B. | 2% |
| C. | 3% |
| D. | 4% |
| Answer» A. 1% | |
| 178. | The longest leaf in a leaf spring is called centre leaf. |
| A. | it is called middle leaf |
| B. | it is called master leaf |
| C. | yes |
| D. | none of the listed |
| Answer» B. it is called master leaf | |
| 179. | If the spring is compressed completely and the adjacent coils touch each other,the the length of spring is called as? |
| A. | solid length |
| B. | compressed length |
| C. | free length |
| D. | none of the mentioned |
| Answer» A. solid length | |
| 180. | If uncompressed length of spring is 40mm and number of coils 10mm, then pitch of coil is? |
| A. | 4 |
| B. | 40/9 |
| C. | 40/11 |
| D. | none of the mentioned |
| Answer» B. 40/9 | |
| 181. | Active and inactive, both types of coils support the load although both don’t participate in spring action. |
| A. | active coils don’t support the load |
| B. | inactive coils don’t support the load |
| C. | both active and inactive don’t support the load |
| D. | both active and inactive support the load |
| Answer» B. inactive coils don’t support the load | |
| 182. | The coefficient of fluctuation of speed is the of maximum fluctuation of speed and the mean speed. |
| A. | product |
| B. | ratio |
| C. | sum |
| D. | difference |
| Answer» B. ratio | |
| 183. | If E = Mean kinetic energy of the flywheel, CS = Coefficient of fluctuation of speed and Δ E = Maximum fluctuation of energy, then |
| A. | Δe = e / cs |
| B. | Δe = e2 × cs |
| C. | topic 4.2 flywheels considering stresses in rims and arms for engines and punching machines |
| Answer» B. Δe = e2 × cs | |
| 184. | The tensile stress in the flywheel rim due to the centrifugal force acting on the rim is given by |
| A. | ρ v2/4 |
| B. | ρ v2/2 |
| C. | 3ρ v2/4 |
| D. | ρ v2 |
| Answer» D. ρ v2 | |
| 185. | In a four stroke cycle engine camshaft revolves at the crank speed. |
| A. | two times |
| B. | half |
| C. | four times |
| D. | three times |
| Answer» B. half | |
| 186. | Crankshafts are usually constructed by |
| A. | casting |
| B. | drop forging |
| C. | drawing |
| D. | extrusion |
| Answer» B. drop forging | |
| 187. | A bearing supports the load acting along the axis of the shaft. |
| A. | thrust |
| B. | radial |
| C. | longitudinal |
| D. | transversal |
| Answer» A. thrust | |
| 188. | In steam and gas turbines, rolling contact bearings are used. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 189. | Deep groove ball bearings creates a lot of noise. |
| A. | yes |
| B. | they create very less noise |
| C. | depends on the application |
| D. | no reference frame for comparison is mentioned |
| Answer» B. they create very less noise | |
| 190. | In angular contact bearings, bearings are required to take thrust load in both directions. |
| A. | 1 |
| B. | 4 |
| C. | 2 |
| D. | 3 |
| Answer» C. 2 | |
| 191. | Which of the following isn’t the property of taper roller? |
| A. | high rigidity |
| B. | easy dismantling |
| C. | take low radial and heavy loads |
| D. | all are the properties of tapper roller |
| Answer» C. take low radial and heavy loads | |
| 192. | Which of the following cannot take radial load? |
| A. | cylindrical roller bearing |
| B. | taper roller bearing |
| C. | thrust ball bearing |
| D. | none of the listed |
| Answer» C. thrust ball bearing | |
| 193. | There are common types of bevel gears. |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 194. | Miter gears are the bevel gears mounted on shaft which are intersecting at angle greater than 90. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 195. | In hypoid bevel gears, shafts may continue past each other. |
| A. | true |
| B. | false |
| Answer» A. true | |
| 196. | Hypoid gears have the following characteristics. |
| A. | curved teeth |
| B. | mounted on non -parallel non intersecting shafts |
| C. | efficiency of 97% |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| 197. | The bearing characteristic number shown in the graph is directly proportional to the unit bearing pressure. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 198. | A single transverse weld is preferred over double transverse fillet weld. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 199. | 5 SELECTION OF ROLLING CONTACT BEARINGS |
| A. | thrust |
| B. | radial |
| C. | longitudinal |
| D. | transversal |
| Answer» A. thrust | |
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