MD Preboard 2011
MD Preboard 2011
MD Preboard 2011
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
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
9. 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
11. Determine the bursting steam pressure of a steel plate with a diameter
of 12 in.a and made of 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
19. Which of the following tools would be most useful when taking leads on
bearings?
A. dividers C. micrometer *
B. outside calipers D. center gage
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 *
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
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
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
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 the cutter which works simultaneously with up cut and down cut
process
A. Side milling cutter.
B. Semi-circular milling cutter.
C. Shell end mill. *
D. 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.
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
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
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 *
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
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 as-
A. 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
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
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 of-
A. 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 *
76. Find the torsional moment in N-m developed when the shaft delivers 40.2
hp at 260 rpm.
A. 901 x 10 to the 3rd power C.1102 x 10 to the 2nd power
B. 901 x 10 to the 2nd power D.1102 x 10 to the 3rd power *
77. Compute how many inch diameter set screws required to transmit 3 HP
at a shaft speed of 900 rpm. The shaft diameter is 1 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
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 in2 * C. 0.327 in2
2
B. 0.1230 in D. 0.5190 in2
84. With an electric arc welding rate rate of 18 in/min, how long will it
take to weld a in. thick plate by 3 ft long seam?
A. 3 min. C. 1.5 min.
B. 2 min. * D. 4 min.
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
91. A steel bar initially free of stress, is held between rigid supports.
Determine the stress in the bar if the temperature drops 130 deg F. (k
= 6.5 x 10-6 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
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 of a round piece of
metal is called a:
A. vise C. V block *
B. jaw holder D. chuck