Me Preboard Md Mar 2011 Set A

Republic of the Philippines PROFESSIONAL REGULATION COMMISSION

Manila BOARD OF MECHANICAL ENGINEERING Registered Mechanical Engineer Licensure Examination Saturday January 29, 2011 01:30 p.m. – 06:30 p.m.

---------------------------------------------------------------SET A  MACHINE DESIGN, MATERIALS AND SHOP PRACTICE INSTRUCTION: Select the correct answer for each of the following questions. Mark only one answer for each item by marking the box corresponding to the letter of your choice on the answer sheet provided. STRICTLY NO ERASURES ALLOWED. Use pencil No.2 only. MULTIPLE CHOICE 1. A thin hollow sphere of radius 10 in and thickness 0.1 in is subjected to an internal pressure of 100 psig. The maximum normal stress on an element of the sphere is A. 2500 psi C. 7,070 psi B. 5000 psi * D. 10,000 psi 2.

In designing a cylindrical pressure tank 3 feet in diameter, a factor of safety of 2.5 is used. The cylinder is made of steel (yield stress = 30 ksi) and will contain pressures up to1000 psi. What is the required wall thickness, t, based on circumferential stress considerations? A. 0.75 in. C. 3 in. B. 1.50 in. * D. 3.75 in.

3.

A flywheel weighing 6 kN has a mean diameter of 90 cm. The maximum speed of the flywheel is 7 rev/sec slowed down to 4 rev/sec during the shearing process. Determine the energy released by the flywheel. A. 7856 kg-m C. 9872 kg-m B. 8145 kg-m D. 8241 kg-m *

4.

When measuring a drill for A. margins * B. flutes

5.

The tool used in precision work to smooth or enlarge holes is called a: A. round out C. reamer * B. drift pin D. protractor

6.

Which of the following chisels would be used for cutting oil grooves? A. diamond-point chisel C. round-nose chisel * B. cold chisel D. hot chisel

7.

Which of the following is not a cut of file? A. smooth C. half-round * B. second cut D. bastard

8.

Which of the following is the smallest size drill?

size measure across the: C. shank D. point

A. # 80 * B. # 60 9.

C. # 1 D. # 0

Two parallel shaft connected by pure rolling turn in the same direction and having a speed ratio of 4. What is the distance of the two shaft if the small cylinder is 8 cm? A. 10 cm C. 18 cm B. 12 cm * D. 20 cm

10. What modulus of elasticity in tension is required to obtain a unit deformation of 0.00107 m/m from a load producing a unit tensile stress of 50, 000 psi? A. 34.5 x 10 6 psi C. 46.7 x 10 6 psi * B. 46.7 x 10 5 psi D. 4.67 x 10 6 psi 11. Determine the bursting steam pressure of a steel plate with a diameter of 12 in.a and made of ¼ in steel plate. The joint efficiency is at 75% and the tensile strength is 55 ksi. A. 3, 440 psi * C. 3, 430 psi B. 3, 437 psi D. 3, 427 psi 12. What is the working strength of a 2 in bolt which is screwed up tightly in a packed joint when the allowable working stress is 11,000 psi? A. 12,400 lb C. 18,700 lb * B. 15,500 lb D. 22,500 lb 13. Which of the following is the largest size drill? A. A C. Z * B. X D. XX 14. The size of a drill is stamped on the: A. point C. margin B. shank * D. flute 15. Which of the following safety precautions should be followed when pouring babbitt? A. operator must wear goggles B. the surface to be babbitted must be free of moisture C. the surface to be babbitted must be clean D. all of the above * 16. Which of the following safety precautions followed when renewing a flange gasket? A. drain the line thoroughly B. tie down isolation valves C. isolate the section to be worked on D. all of the above * 17. Before installing a A. flange faces are B. flange faces are C. isolating valves D. old gasket is in

should

new flange gasket be sure that the: painted absolutely clean * are open place

18. On a standard wire gage: A. #10 is larger than #5

C. # 1is smaller than #2

be

B. #25 is smaller than #20 *

D. #30 is larger than #25

19. Which of the following tools would be most taking leads on bearings? A. dividers C. micrometer * B. outside calipers D. center gage

useful

when

20. The cutting action in on both stokes in A. Open side planer C. Double housing planer B. Pit planer D. Universal planer * 21. The straddle milling is done by means of two A. Side milling cutters * C. Plain milling cutters B. Face milling cutters D. Form cutters 22. The formula to find out the number of turn of the crank simple indexing is A. T=20/N C. T=N/20 B. T=40/N * D. T=N/40 23. In a standard dividing head the ratio between the worm wheel and the worm is A. 10:1 C. 20:1 D. 30:1 D. 40:1 * 24. There are two different movements of the crank in A. Simple indexing C.Compound indexing * B. Differential indexing D. Angular indexing 25. In a vertical milling machine the spindle is situated to the A. Horizontal C. vertical * B. Angular D. None of the above 26. Planer type built machine is built up for work of A. light duty C. heavy duty * B. medium duty D. None of the above 27. In a straddle milling operation how many cutters are used to mill the work? A. One C. Two * B. Three or more D. Any one of the above 28. All four compression coil spring support one load of 700 kg/mm. All four springs are arranged in parallel and rated same at 0.609 kg/mm. Compute the deflection in mm. A. 64 C. 178 B. 147 D. 287 * 29. A body weighing 1000 lb falls 6 inches and strikes a 2000 lb per in spring. The deformation of the spring is: A. 1 in C. 3 in * B. 2 in D. 6 in 30. A 60 inch diameter steel pipe, 3/8 inch thick, carries water under a pressure head of 550 ft. Determine the hoop stress in the steel. A. 34,320 psi C. 19,066 psi * B. 25,780 psi D. 15,920 psi

31. The maximum moment induced in ft span, by a 2000 pound load A. 125,000 ft – lb B. 15,000 ft – lb

a simply supported beam of 20 at midspan is C. 30,000 ft – lb D. 10,000 ft – lb *

32. Determine the length of belt needed for a two flat belt pulleys having a diameter of 70 cm and 30 cm. The center distance is 400 cm and pulleys rotate in same direction. Assume power transmitted is 10 hp at 200 rpm. A. 958 cm * C. 589 cm B. 859 cm D. 895 cm 33. A round steel bar 12 inches long is to withstand a dead load of 40,000 lb in compression. The rod must not shorten more than 0.004 inch and have a factor safety of at least 10. Assume the ultimate strength of the material to be 110,000 psi and modulus of elasticity to be 15,500,000 psi. Determine the diameter of the rod. A. 2.14 in. C. 4.14 in. B. 3.14 in * D. 5.14 in. 34. How long will it take to saw a rectangular piece of steel plate size ½ “ x 4’ x 8’ the length of cut is 4 ft. The power hacksaw makes 120 rpm and the feed per stroke is 0.008 in.? A. 48 min. C. 50 hr B. 0.83 hr * D. 52 min. 35. For gear cutting which cutter is used? A. End mill cutter C. Plain milling cutter B. Form relieve cutter * D. All of the above 36. In a slotter, the table gets ___ different feeds A. One C. Two B. Three * D. None of the above 37. If a clearance of a cutting edge is 15 deg, the lip (wedge) angle in 75 deg, the rake angle will be A. 80 deg C. 70 deg B. 10 deg * D. None of the above 38. The approximate hardness of HSS end mill cutter is A. 45 HRC C. 52 HRC B. 62 HRC * D. 72 HRC 39. When the feed motion takes place in a slotting machine A. during the cutting motion. B. after each forward stroke. C. at the end of return motion. D. after each double stroke. * 40. Which of the following conditions may cause error during knurling? A. to much longitudinal feed. * B. clamped length of tool too short. C. surface speed too low. D. unnecessary support with tail stock center.

41. Mark the milling method during which the formation of the chatter marks is very likely A. during down cut milling with a straight tooth cutter. B. during up cut milling with a straight tooth cutter. * C. during face milling with a straight tooth cutter. D. while using spiral tooth cutter. 42. Mark down A. B. C. D.

the cutter which works simultaneously with up cut and cut process Side milling cutter. Semi-circular milling cutter. Shell end mill. * Plain milling cutter.

43. A polygon with 9 flats is to be milled using the indexing head. The indexing head transmission ratio is 40:1.Determine the number of crank rotation and mark the correct answer A. 9 full rotation. B. 5 full rotation, 2 holes on the 36 hole circle. C. 4 full rotation, 12 holes on the 27 hole circle. * D. 2 full rotation, 16 hole on the 47hole circle. 44. Where the relieved cutters are reground? A. on the circumstances B. relieved cutters are not reground C. on the flank * D. on the side faces 45. What happens if the job is loosely fitted between centers in cylindrical grindings? A. the job will be out of round. * B. the job will be oversize. C. the job will be thrown out. D. the job will not rotate. 46. Internal and external taper on cylindrical jobs are ground in A. plain cylindrical grinding machine. B. universal cylindrical grinding machine. * C. internal grinding machine. D. centreless grinding machine. 47. Which of the following is used to clean the gauge blocks before and after use? A. Brush B. Cotton waste C. Chamois leather or lenen cloth * D. None of the above 48. The grade of grinding wheel depends upon A. Grain size C. Structure B. Kind of abrasive D. Hardness of bond * 49. Which kind of bond is commonly used? A. Vitrified * C. Rubber B. Shellac D. None of the above

50. The symbol conventionally used for resinoid bond is A. ‘V’ B. ‘B’ *

C. ‘R’ D. ‘E’

51. A grinding wheel is marked as 51A 46L 5V 23, out of these 5 means A. Kind of abrasive C. Kind of bond B. Structure * D. Grain size 52. Balancing of grinding wheel is done to A. make the outside diameter concentric with the bore. B. make the sides of wheel parallel. C. equalize the weight in every portion of the wheel. * D. None of the above. 53. Taps are resharpened by grindings A. Flutes * C. Threads B. Diameter D. Relief 54. The purpose of______is to prevent gears from jamming together and making contact on both sides of their teeth simultaneously A. tooth fillet C. backlash * B. stress relieving D. all of these 55.

Choose the economical type of material for gears that give/sustain good operating quality/life for intended operation A. plane carbon steel C. all of these B. high alloy steel D. heat treated carbon steel *

56. Allowance added in the casting pattern to compensate for the contraction of metal A. tapering allowance C. finish allowance B. shrinkage allowance * D. draft pattern 57. Ratio of the angle of action to the pitch angle A. contact ratio * C. ratio of gearing B. approach ratio D. module 58. The principle materials used in the production of metal working tools: A. high carbon steel * B. titanium, phosphorous C. tungsten, silicon, hadfield Mn D. vanadium, chromium, molybdenum 59. Also called eccentrically loaded bearing is ________. A. full bearings C. partial bearing B. offset bearing * D. fitted bearings 60. In the selection of wire rope, regular lay means wires and strands are arranged in the following manner: A. twisted in the same direction B. twisted in opposite direction* C. twisted in any direction D. twisted in along direction

61. In involute teeth, the pressure angle is often defined as the angle between the line of action and the line of tangent to the pitch circle. It is also termed asA. helix angle C. Angle of obliquity * B. angle of recess D. Arc of action 62. Height of tooth above pitch circle or the radial distance between pitch circle and top land of the tooth. A. top root C. land B. addendum * D. hunting tooth 63. The function of clutch in the machine tool is? A. lowering of drive speed B. to disconnect or connect at will the drive * C. alignment of drive shaft D. to insure that two shaft line up at high speed 64. The rule of thumb in journal bearing design; the clearance ratio/clearance should be. A. 0.0090 C. 0.0010 * B. 0.0042 D. 0.00120 65. Cold rolled shafting is not available in diameter larger than__________ A. 6 inches C. 6 ½ inches B. 5 inches * D. 5 ½ inches 66. The cast iron flywheels factor of safety of______ A. 14 to 15 B. 10 to 13 *

are

commonly

designed

with

a

C. 8 to 9 D. 6 to 12

67. A pair of equal and opposite (not collinear) forces that tend cause a rotation of a body A. couple * C. equilibrium B. centroids D. vector 68. The ratio of the pitch diameter in inches to the number of teeth A. pitch circle C. module B. English module * D. pitch diameter 69. When high strength and durability are a requirements for choosing gear materials it is preferable to use_________material A. hardened bronze C. phenolic laminated B. steel * D. white iron 70. The distance between similar, equally-spaced tooth surfaces in a given direction and along a given line. A. pitch circle C. pitch * B. pitch plane D. pitch diameter 71. The use of hardened steel for the mating metal gear appears to give the best results and longer operational life. The usual hardness is in the range ofA. over 600 BHN * C. below 350 BHN B. 300 to 400 BHN D. over 400 BHN

72. Continuous stretching under load even if the stress is less than the yield point A. plasticity C. creep * B. elasticity D. ductility 73. The most known lubricants being utilized in whatever category of load and speed are oil, air, grease and dry lubricants like A. bronze C. silicon B. lead D. graphite * 74. A coupling that allows axial flexibility/movement in the operation. Made of alternate bolting of steel, leather, fabric and/or plastic material into the two flanges A. Flexible disk coupling * B. flexing Oldham coupling C. Flexible toroidal spring coupling D. Elastic-material bonded coupling 75. It consists of two cranks, a stationary piece called the line of centers and the connecting rod is a A. five-bar linkage C. three-crank linkage B. four-crank braces D. four-bar linkage * 76. Find the torsional delivers 40.2 hp at A. 901 x 10 to the B. 901 x 10 to the

moment in N-m developed when the shaft 260 rpm. 3 rd power C.1102 x 10 to the 2 nd power 2 nd power D.1102 x 10 to the 3 rd power *

77. Compute how many ¼ inch diameter set screws required to transmit 3 HP at a shaft speed of 900 rpm. The shaft diameter is 1 ¼ in A. 2 C. 4 * B. 3 D. 2.5 78. A pair of gear and pinion having a ratio of 4 with the gear having 100 teeth and the pinion with 25 teeth. Find the circular pitch, if the center distance is 15 and the pitch is at 6. A. 0.94 C. 0.610 B. 0.754 * D. 0.552 79. A gear of 80 teeth and a pinion of 20 teeth has a gear and pinion ratio of 4. Find the center distance , in inches, if the circular pitch is 0.885. A. 14.1 * C. 16.1 B. 15.1 D. 17.1 80. The section modulus of a circle of radius 5 cm is equal to: A. 58.2 cm 3 C. 98.2 cm 3 * B. 78.2 cm 3 D. 108.2 cm 3 81. A hollow shaft with outside diameter of 14 cm and wall thickness of 0.08 cm transmits 200 kW at 400 rpm. What must be the angular deflection of the shaft if the length is 5 meters? Take G = 12,000,000 psi. A. 0.019 deg C. 1.94 deg

B. 1.14 deg *

D. 2.44 deg

82. Compute the safe wall thickness of a 90 cm diameter steel tank. The tank is subjected to 7 MPa pressure and the steel material has yield stress of 220 MPa. Use a factor of safety of 3. A. 4.3 cm * C. 3.2 cm B. 3.8 cm D. 2.5 cm 83. A bolt has a tensile load of 300 lbs. The bolt is made of SAE 1040 material with Sy = 55 ksi, what is the stress area of the bolt? A. 0.1023 in 2 * C. 0.327 in 2 B. 0.1230 in 2 D. 0.5190 in 2 84. With an electric arc welding rate rate of 18 in/min, how long will it take to weld a ½ in. thick plate by 3 ft long seam? A. 3 min. C. 1.5 min. B. 2 min. * D. 4 min. 85. Determine the power transmitted, in kW, by a main power transmitting steel shaft with 2 3/8 inches in diameter using SAE 1060 material mounting a 12 inches pulley at a speed of 170 rpm. A. 21.3 * C. 28.5 B. 25.8 D. 0.75 86. Determine the polar section modulus, Z p (in3) of a shaft delivering 5 hp at 150 rpm. The diameter of the shaft is 1 inch and allowable stress of 6000 psi. A. 0.175 C. 0.489 B. 0.196 * D. 0.895 87. Compute the deflection of a 20 coils helical spring having a load of 120 kgs. The modulus of elasticity in shear of spring is 98 GPa, outside diameter of 10 cm and wire diameter of 10 mm. The spring is squared and ground ends. A. 162.1 mm C. 134.1 mm B. 154.4 mm D. 126.1 mm * 88. The torsional deflection of steel shaft is 0.6 deg per meter length. The shear stress is 60 MPa. Compute the diameter of the shaft in mm. Steel modulus of elasticity is 79 GPa. A. 90 mm C. 130 mm B. 105 mm D. 145 mm * 89. What is the size of an air cylinder operating at 10 bar with a required force of 7854 N? Use a load ratio of 90%. Load ratio means the ratio of required force and theoretical force. A. 100 mm C. 150 mm B. 105 mm * D. 300 mm 90. A steel rod 30 ft long used in a control mechanism must transmit a tensile force of 980 lb without stretching more than 1/8 in. nor exceeding an allowable stress of 20,000

psi. What must the diameter of the rod be? (E = 30 x 10 6 psi ) A. 1/4 in C. 1/2 in B. 3/8 in * D. 3/4 in 91. A steel bar initially free of stress, is held between rigid supports. Determine the stress in the bar if the -6 temperature drops 130 deg F. (k = 6.5 x 10  per deg F) A. 11,400 psi C. 20,600 psi B. 15,600 psi D. 25,400 psi * 92. When working on bearings and checking for high spots, it is customary to apply: A. white lead C. dykem blue B. red lead D. Prussian blue * 93. If you wanted to check the face of a pump slide valve or other flat-faced valve, you could check for trueness on a: A. flat board C. piece of glass B. surface plate * D. bearing plate 94. Before splicing electric wires, they should be: A. tinned C. soldered B. cleaned and tinned * D. insulated 95. Which of the following is not a standard thread form? A. Square C. Double flute * B. American National D. 60 deg. sharp V 96. Hand taps are provided in sets of three called: A. taper, plug and end C. taper, plug and bottom * B. short, taper and bottom D. short, medium and long 97. When preparing to tap a hole, the size of the drill will be A. equal to the size of the tap B. larger than the size of the tap B. smaller than the size of the tap * D. none of the above 98. When preparing to tap a hole for a pipe fitting the size of the drill will be : A. larger than the tap size * B. smaller than the tap size C. equal to the size of the tap D. none of the above 99. Which of the following does not have to be lubricated when drilling? A. steel C. monel B. brass * D. tool steel 100. The tool to use when cutting a hole in the side round piece of metal is called a: A. vise C. “V” block * B. jaw holder D. chuck

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