TOPICS COVERED:
- Factor of Safety
- Bearings
- Shafts
- Thermal Expansion
- Belts
- Gears
- Machine Shop Practice
- Pressure Vessels
- Cams
- Chains and Sprockets
- Materials Testing
Exercises MACHINE DESIGN
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1. How many 1-in diameter and 1/8-in steel plate that can be punched by means of an 83,654 lb force, if the ultimate shear stress of the plate is 34,800 psi. Use a factor of safety of 4. a. 5 b. 6 c. 7 d. 8 2. The main bearings of an engine are 155 mm diameter and 290 mm long and support a load of 4500 kg midway between the bearings. Find the bearing pressure, in kPa. a. 372.32 b. 491.05 c. 542.82 d. 603.22 3. Two cylinders in opposite direction having a speed ratio of 3 have a center distance of 35-in. Find the diameter of larger cylinder. a. 17.5 in b. 45.5 in c. 52.5 in d. 65.5 in 4. A steel shaft of 60 mm in diameter and 1.5 m length is restrained from moving. If its temperature is changed by 85 deg C, what compressive stress, in kPa is induced? a. 325,331.6 b. 228,498.5 kPa c. 300,342.9 kPa d. 210,112.4 kPa 5. The maximum shear stress in a solid round shaft subjected only to torsion occurs: a. On the surface of the shaft b. Only on planes perpendicular to the axis of the shaft c. On the principal planes d. In planes containing the axis of the shaft 6. What is the color of pipe for flammable or oil-mineral vegetable? a. Brown b. Natural c. Violet d. red 7. Which of the following metals are never used for conducting electricity because of its very high resistance a. Mercury b. Nickel c. Iron oxide d. Aluminum oxide 8. An annealing process whereby combined carbon in white cast iron is transformed wholly or in part to temper carbon a. Tempering b. Drawing c. Malleabilizing d. Normalizing 9. Find the polar moment of inertia of a rectangular beam with dimension of 3.5-in and 6-in. a. 80.21 b. 78.31 c. 84.4 d. 87.3 10. Three cylinders A:B:C has a speed ratio of 4:3:5 are externally in contact to each other. If the center distance between cylinder A and C is 35-in, find the diameter of cylinder B. a. 15.31 in b. 28.31 in c. 33.46 in d. 20.90 in 11. An iron rod 5 m long and 0.6 cm2 in cross section stretches 1 mm when a mass of 250 kg is hang on it. Compute the modulus of elasticity of the iron. a. 204 GPa b. 158 GPa c. 230 GPa d. 221 GPa 12. Find the stress developed in the shaft if it is heated from 35 deg C to 98 deg C. a. 152.4 MPa b. 163.2 MPa c. 120.0 MPa d. 132.8 MPa 13. Find the force needed to punch 1-3/4 inches hole from a 1-1/2 inches thick plate. a. 156 tons b. 210 tons c. 122 tons d. 130 tons 14. A 28-n long rod (E = 3 x 107 psi, k = 6 x 10-6 in/in-oF) with a 2-in2 cross section is fixed at both ends. If the rod is heated to 55 deg C above the neutral temperature, what is the stress? a. 15,330 psi b. 16,512 psi c. 17,820 psi d. 14,250 psi 15. A SAE 1040 has 1% Mn. The percent carbon content is in the range of: a. 0.35/0.42 b. 0.37/0.44 c. 0.28/0.32 d. 0.40/0.47 16. Moment of Inertia of a square cross section with a dimension “a” in each side: a. 0.1666a4 b. 0.208a3 c. a4/12 d. a4/16 17. SAE 2xxx or AISI 2xxx is ____ steel. a. Chromium b. Manganese c. Stainless d. Nickel 18. Steel designation of nickel-chromium a. SAE 3xxx b. SAE 4xxx c. SAE 5xxx d. SAE 7xxx 19. A 25.4 mm diameter and 210 m solid steel rod has an applied load of 600 kN in tension. If the Poisson’s ratio is 0.30, find the decrease in its diameter, in mm. a. 32.2 x 10-3 b. 43.6 x 10-3 c. 52.1 x 10-3 d. 46.9 x 10-3 20. Improves red hardness of steel a. Boron b. Lead c. Cobalt d. Chromium 21. If the ultimate shear strength of a steel plate is 45,000 psi, what force is necessary to punch a 0.85-in diameter hole in a 0.65-in thick plate? a. 78,107.8 lbs b. 56,100.5 lbs c. 82,130.1 lbs d. 73,451.5 lbs 22. A steel tie rod on bridge must be made to withstand a pull of 5000 lbs. Find the diameter of the rod assuming a factor of safety of 3 and ultimate shear stress of 62,000 psi. a. 0.452 in b. 0.555 in c. 0.361 in d. 0.650 in 23. The torque transmitted in a belt connected to 310 mm diameter pulley is 5 kN-m. Find the power driving the pulley belt if the speed is 22 m/s.
a. 542.7 kW b. 652.1 kW c. 709.7 kW d. 421.8 kW 24. A 15 cm pulley turning at 620 rpm is driving a 25 cm pulley by means of a belt. If the total belt slip is 6%, determine the speed of the driving gear. a. 451.1 rpm b. 220.0 rpm c. 532.8 rpm d. 349.7 rpm 25. Find the belt length of an open belt to connect the 7 cm and 14 cm diameter pulley at a center distance of 75 cm. a. 175.2 cm b. 164.1 cm c. 210.4 cm d. 184.4 cm 26. Absorb and equalize energy in case the resistance to motion varies, or used to equalize the energy exerted and the work done. a. Flywheel b. Balanced wheel c. Flywheel pulleys d. All of the above 27. Arc of the pitch circle through which a tooth travels from its contact with the mating tooth at the pitch point to the point where the contact ceases. a. Arc of approach b. Arc of recess c. Arc of action d. Arc of contact 28. Cheapest shaft material available in the market a. SAE 1030 b. SAE 4130 c. SAE 5120 d. SAE 1117 29. Avoid using ____ in a lathe machine operation. a. Outside caliper b. Measure ruler c. Wooden shoes d. Safety gloves 30. Find the angle of contact on the small pulley for a belt drive with center distance of 70-in and with pulley diameter of 6-in and 12-in, respectively. a. 170.0 deg b. 175.0 deg c. 180.5 deg d. 185.0 deg 31. A pair of straight tooth bevel gear connects a pair of 90 deg shafts. The velocity ratio is 4 to 1. What is the cone pitch angle of smaller gear? a. 70.2 deg b. 76.0 deg c. 82.6 deg d. 87.4 deg 32. A straight tooth bevel gear has a face with of 5” and a pitch diameter of 15-in with cone pitch angle of 40 deg. If the torque on the gear is 8500 in-lb, what is the tangential force on the gear? a. 1302.2 lbs b. 1442.4 lbs c. 1560.8 lbs d. 1200.5 lbs 33. A 20 deg full depth straight tooth gear has a face width of 2-3/4 inches and a pitch diameter of 14 inch with cone pitch angle of 37.5 deg. Find the mean diameter. a. 9.2 in b. 12.3 in c. 14.6 in d. 16.2 in 34. A helical gear having a helix angle of 24 deg and pressure angle of 20 deg. Find the pressure angle normal to the teeth. a. 15.2 deg b. 20.2 deg c. 18.4 deg d. 24.3 deg 35. A 28-teeth helical gear having a pitch diameter of 8 has a helix angle of 23 deg. Find the circular pitch in a plane normal to the teeth. a. 0.8262 b. 0.5211 c. 0.7754 d. 0.6501 36. To avoid scoring in the bearing surface and the shaft due to contamination/absorption of fine dirt in the bearing during operation/lubrication, the bearing material to apply should have good _____ properties. a. Corrosion resistance c. Corrosion resistance conformability b. Embeddability d. Anti-scoring 37. In itself, it is a lubricant and usually one of the important elements in casting non-ferrous metals like bronze, for example. a. Lead b. Antimony c. Zinc d. Babbitt 38. For large speed ratio and large sprocket utilized it is recommended cast ____ material since the large sprocket teeth are having fewer engagements. a. Alloyed steel b. Malleable iron c. Heat treated steel d. Iron 39. To enhance mechanical properties, fabrication characteristic or any other attributes of steel, some elements are added in melting specific ranges or minimums aside from carbon and generally termed _____. a. AISI steel b. SAE steel c. Alloy steel d. Bessemer steel 40. A 20-teeth helical gear has a pitch diameter of 7-in. Find the diametral pitch of the gear. a. 5.21 b. 4.21 c. 3.11 d. 2.86 41. Gears are manufactured usually in the following processes: milling, generating, shaving, grinding and ____ which is also used. a. Blanking b. Molding c. Dinking d. Heat treatment 42. A low coefficient of expansion, corrosion resistant, weak in strength and used for non-ferrous application as an alloy element. a. Aluminum b. Copper c. Aluminum oxide d. Copper oxide 43. _____ is a kinematic chain in which one link is considered fixed for the purpose of analysis but motion is possible in other links. a. Belting b. Mechanism c. Frame d. Sprocket chain 44. This particular cutting tool material could withstand cutting temperature of 1800 deg F and higher at cutting speed beyond those possible with other cutting tool materials a. Carbide grade b. Cubic boron nitride c. Titanium carbide d. Ceramic A 3.5 in diameter shaft is driven at 3500 rpm by a 410 HP motor. The shaft drives a 50 in diameter chain sprocket having an output efficiency of 80%, find: 45. Torque in the shaft a. 6298.1 in-lbs b. 8082.5 in-lbs c. 5423.7 in-lbs d. 7382.9 in-lbs 46. The output force on the sprocket a. 300.0 lbs b. 230.1 lbs c. 295.3 lbs d. 252.6 lbs 47. The power delivered by the sprocket a. 328 hp b. 285 hp c. 420 hp d. 252 hp 48. A double thread worm gear has a lead angle of 7.25 degrees and pitch radius of 2-3/4 inches. Find the pitch of the worm. a. 2.0 in b. 1.1 in c. 3.1 in d. 2.6 in 49. Determine the safe wall thickness of 60-in steel tank with internal pressure of 10 MPa, The ultimate stress is 295 MPa. The factor of safety is 4. a. 3 in b. 4 in c. 5 in d. 6 in 50. Find the minimum thickness, in inches of steel sphere to contain 1800 psi. The diameter of the sphere is 55-in and the allowable maximum normal stress is 37000 psi. a. 0.669 in b. 0.250 in c. 0.750 in d. 1.0 in 51. Type of chuck wherein the work piece with standard diameter or size could be attached fast and quick especially small size work of mass production. a. Steady center rest b. Clamp toe dog c. Collet attachment d. Lathe drive plate 52. Intermediate gear is also called ____ gear in a gear train arrangement a. Pinion b. Third gear c. Idler d. Mounted gear 53. The recommended age limit of the fire tube boilers a. 40 years b. 35 years c. 30 years d. 50 years 54. The factor of safety generally applied in wire rope design starts at 3-4 for standing rope application, 5-12 operating rope and ____ for hazard to life and property application like foundry operation. a. 7-10 b. 8-10 c. Higher values d. 10-18 55. Determine the bursting pressure of steel with diameter of 12-in and made of 1/2-in thick plate. The joint efficiency is 85% and the tensile strength is 65 ksi. a. 8230.0 psi b. 9208.3 psi c. 10120.5 psi d. 7500.0 psi 56. Calculate the cutting speed, in fpm of a workpiece with 1-3/4 inches diameter and running at 120 rpm. a. 45.2 fpm b. 35.8 fpm c. 54.9 fpm d. 41.3 fpm A four-wheel vehicle must develop a draw-bar pull of 18,500 lbs. The engine which develops 600 hp and drives through a gear transmission a 34-tooth spiral bevel pinion gear which meshes with a spiral bevel gear having 52 teeth. This gear is keyed to the drive shaft of the 50 in diameter rear wheels of the vehicle. 57. What transmission gear ratio should be used if the engine develops maximum torque at 1800 rpm? a. 17:1 b. 15:1 c. 18:1 d. 14:1 58. Select the axle diameter for an allowable torsional stress at 13,000 psi, the efficiency of the bevel differential is 85%. a. 3.50 in b. 4.50 in c. 5.50 in d. 2.50 in 59. During a punching process of 360 kg flywheel, the speed varies from 220 rpm to 160 rpm with 1 m mean diameter. Determine the kinetic energy required. a. 12.3 kJ b. 16.2 kJ c. 11.3 kJ d. 14.7 kJ 60. A water tank 12 m x 14 m is completely filled with water. Find the minimum thickness of the plate if the stress is limited to 60 MPa. a. 10.2 mm b. 18.3 mm c. 8.2 mm d. 13.7 mm 61. The maximum stress induced in a material when subjected to intermittent or repeated load with causing failure is called ___. a. Elastic limit b. Ultimate torque c. Ultimate stress d. Endurance limit 62. A tool not belonging to the group: a. Trammel b. Hermaprodite caliper c. Double VEE block d. Divider 63. _____ is the theoretical profile of the thread for a length of one pitch in the axial plane on which the design forms of both the external threads are based. a. Design form of external thread b. Basic profile of thread c. Basic form of thread d. Effective thread 64. _____ thread is used where the thread requires great strength and usually cut square on one side and slanting on the other side. a. Buttress b. Square c. Double d. Janno 65. What pressure is required to punch a hole 3-in diameter through a 1/4-in thick plate. a. 60 tons b. 55 tons c. 65 tons d. 70 tons 66. Plus or minus of the tolerance is also called: a. Bilateral tolerance b. Total tolerance c. Unilateral tolerance d. None of the above 67. Find the polar moment of inertia of a hollow shaft with OD = 8” and ID = 6”. a. 65.3 b. 68.7 c. 74.2 d. 55.1 68. Compute for the diameter (in inches) of a SAE 1030 steel shaft to transmit 18 HP at 130 rpm with torsional deflection of 0.08 degree/foot length as required. a. 6.7 in b. 9.8 in c. 5.5 in d. 7.3 in 69. Find the power, in kW transmitted by a main power transmitting shaft with diameter of 60 mm and speed of 250 rpm. a. 25 b. 28 c. 36 d. 31 70. Determine the average time to cut by automatic oxy-acetylene (machine) crosswise a 4 ft x 8 ft x 3 in thick steel plate. (Oxy acetylene cutting speed = 10 inches per minute). a. 252 sec b. 233 sec c. 288 sec d. 245 sec 71. For economical cost in the manufacturing large worm gears the following materials are usually applied a. Bronze rim with cast steel spider b. Cast steel rim with brass spider c. Alloyed aluminum rim with cast iron spider d. Cast iron rim with bronze spider 72. All terms and abbreviations deal with wire rope arrangement except this ___ which deals with wire rope materials strength. a. IWRC b. Mps c. Lang lay d. Preformed 73. Relief angle of single-point cutting test in cutting mild steel, cast iron and other average work as recommended should be in the ranges of ____ degrees for high speed tools. a. 10 to 15 b. 12 to 16 c. 8 to 12 d. 5 to 7 74. Determine the width of 6 ply rubber belt required for a ventilating fan running at 180 rpm driven from a 14 inch pulley on a 80 HP at 860 rpm. The center distance between pulley is 14 ft and the rated belt tension is 75 lb/in width. a. 10.2 in b. 9.3 in c. 13.2 in d. 11.7 in 75. Compute how many 3/8 inch diameter set screws required to transmit 5 hp at a shaft speed of 800 rpm. The shaft diameter is 1.5 inch. a. 4 b. 3 c. 2 d. 5 A cylindrical tank is subjected to a maximum pressure of 3 N/mm2. The inside diameter is 1.8 m (Double riveted) while the riveted joint has a longitudinal pitch of 55 mm and there are two straps placed. The design stress for the plate and the rivet are 170 MPa and 220 MPa, respectively. Find: 76. The thickness of the plate. Let the joint efficiency to be 80%. a. 15.22 mm b. 20.21 mm c. 17.34 mm d. 19.85 mm 77. The diameter of the rivet hole a. 12.31 mm b. 18.34 mm c. 14.13 mm d. 16.00 mm 78. The efficiency of the longitudinal joint a. 74.31% b. 70.23% c. 77.82% d. 79.12% A circular cam 9 inches in diameter rotates off-center with an eccentricity, e=1 inch and operates the roller follower, b, that is carried by the arm as shown in the sketch below. The roller follower is held against the cam by means of an extension spring C. Assuming that the force between the follower and the can to be approximately 60 pounds at the low position, and 90 pounds at the high position. The ratio of mean diameter of coil to that of the wire diameter is 8.0. The spring is attached at the third point of the arm. Take Ss for steel as 60,500 psi.
79. Wire diameter
a. 0.50 in b. 0.35 in c. 0.75 in d. 0.25 in 80. Outside diameter of spring a. 2.0 in b. 2.5 in c. 3.0 in d. 3.5 in 81. Number of active coils you would recommend. a. 10 b. 8 c. 12 d. 14 A V-belt is to transmit 65 HP to a NH3 compressor. The sheave is 205 mm in diameter and turns at 1200 rpm, while the larger sheave turns at 500 rpm. The service factor may be taken as 2.0 and the center distance is equal to the diameter of the larger sheave. Determine: 82. Length of the belt, in inches a. 80.1 in b. 85.8 in c. 90.3 in d. 75.6 in 83. The number of belts required. Let: small diameter factor, Kd=1.13, correction factor for belt length, KL=1.02, and correction factor for an arc contact other than 180o, Kθ=0.90 a. 21 b. 24 c. 26 d. 18 84. What type of leather belting should be used at an ambient temperature above 140 deg F and possible acid liquid coming in contact with the belt? a. Combination of oak b. Oak tanned c. Mineral tannedd. None of these 85. Treatment process that produces a residual compressive stress at the surface (which occupy more volume) and residual tension on the inside that results in considerable increase in fatigue strength for members on torsion/bending. a. Shallow quenching b. Quenching c. Heavy oil quenching d. Partial quenching 86. It is hardening treatment whereby a cast metal is being heated to a very high temperature then suddenly subjected to rapid cooling to improve hardenability or wear resistance is called _____. a. Tempering b. Normalizing c. Quenching d. Annealing 87. Deflection of beam is: a. Inversely proportional to the weight imposed times the length Due to the high cost of electrical power, high maintenance cost and high investment of air-conditioning units, air circulating fans are becoming popular particularly in rural areas. A restaurant owner has decided to install a used fan that could deliver 20,000 CFM of air when running at 300 rpm. The fan is estimated to require at least 5.5 HP to deliver the volume of air needed. The owner also has a second-hand motor rated at 6 HP and 1800 rpm. He would like you to use a standard chain and sprocket for the transmission. If the suitable size of the chain is ½-in pitch and with 18 teeth for small sprocket, find: 88. Diameter of small sprocket, in inches a. 3.28 b. 2.87 c. 4.02 d. 5.00 89. Number of teeth of larger sprocket a. 126 b. 132 c. 140 d. 108 90. Diameter of larger sprocket, in inches a. 14.31 b. 12.92 c. 17.19 d. 20.12 91. Recommended center distance, in inches a. 18.63 b. 14.22 c. 20.12 d. 23.21 92. Length of chain, in inches a. 82 b. 73 c. 93 d. 80 93. Safety features that must be placed and maintained at Machine, Blacksmith, Welding and Foundry Shops a. Safety notices in markers/boards b. Walk away guide c. Safety goggles d. All of these 94. The ideal thickness of the cutter at the pitch line for cutting helical gears should be _____ of the normal pitch. a. 3/8 b. ½ c. ¾ d. 5/16 95. In drilling soft materials use cutting angle as low as 40 degrees but extremely hard material up to ____ degrees is recommended a. 65 b. 75 c. 80 d. 70 96. In general, the design stress and factor of safety are related as follows: a. Design stress = ultimate stress divided by factor of safety An air compressor is driven by a 8.5 hp electric motor with a speed of 1800 rpm with standard A-60 V belts with a standard belt length of 1557 mm. The pitch diameter of the small sheave is 120 mm and the larger sheave is 210 mm. Service factor is 1.5. Find the following: 97. Center distance between sheaves a. 697.76 mm b. 650.21 mm c. 782.23 mm d. 707.72 mm 98. Arc of contact on the small sheave a. 155 deg b. 143 deg c. 173 deg d. 164 deg 99. Arc of contact on the larger sheave a. 165 deg b. 187 deg c. 132 deg d. 192 deg 100. A machinery operation whereby done with the work accurately fastened has a reciprocating (forward and backward) motion and the tool head is stationary a. Planing b. Reaming c. Turning d. Shaping |
