Mechanical Engineering Review Online

1. How much will a 35 ft cable be lengthened if the unit strain is 0.0008 in/in?

a. 0.2543 in

b. 0.1182 in

c. 0.4120 in

d. 0.3350 in

2. A 12 HP split-phase motor running at 1700 rpm is to be used to drive a rotary pump which operates 24 hrs a day. The pump should run at approximately 1200 rpm. The center distance should not exceed 45-in. Space limits the diameter of the driven sheave to 12-in. Diameter of small sheave is 7.5-in. Compute for the length of the belt.

a. 110 in

b. 100 in

c. 121 in

d. 130 in

3. In problem 2, compute for the belt speed, in fps.

a. 60.6

b. 51.3

c. 55.6

d. 64.8

4. A helical compression spring, made of music wire, has a wire size of 0.090-in, an outside diameter of 9/16-in, a free length of 4-1/8 in. 22 active coils and both ends squared and ground. Determine the shear-stress concentration factor.

a. 2.111

b. 1.095

c. 1.231

d. 2.981

5. In problem 4, determine the Bergstrasser factor.

a. 1.278

b. 1.857

c. 2.331

d. 2.817

6. The differential of the shear equation is which one of the following:

a. Tensile strength of the beam 

b. Load of the beam

c. Bending moment of the beam

d. Slope of the elastic curve

7. When two pieces are to maintain permanently together but the shape of one or both would make it impracticable or impossible to force one within the other, the enveloping piece is heated and thereby expanded sufficiently to slide over the other and then cooled slowly with water.

a. Shrink fit

b. Force fit

c. Slip fit

d. Expand allowance

8. A cutting tool used in cutting things as keyways, narrow curves, square corners, or slots and this tool is narrow in width and can also be used to chip flat surfaces.

a. Cape chisel

b. Round chisel

c. Flat chisel

d. Diamond-point chisel

9. A 1.8 HP electric motor runs at 1500 rpm in a clockwise rotation. Keyed to the motor shaft is an 18-tooth helical pinion having a normal pressure angle of 20 deg, a helix angle of 30 deg, and a normal diametral pitch of 12 teeth/in. Calculate the pitch line velocity, in fps.

a. 8.35

b. 7.31

c. 11.34

d. 12.08

10. In problem 9, compute the transmitted load, in lbs.

a. 80.35

b. 87.33

c. 92.57

d. 95.37

11. A thin-walled cylinder is 25-in diameter (inside). The internal fluid pressure is 160 psi. The wall thickness is 0.125-in. Determine the induced stress in the cylindrical wall.

a. 15000 psi

b. 16000 psi

c. 17000 psi

d. 18000 psi

12. A coil spring is to have a spring index of 6 and is to deflect 1/2-in under a load of 60 lb. G=12 x 106 psi and spring has 15 active coils. Compute the wire diameter.

a. 0.4852”

b. 0.2592”

c. 0.5783”

d. 0.3902”

13. In problem 12, calculate the mean diameter.

a. 2.55”

b. 1.56”

c. 3.33”

d. 4.01”

14. A curved formed by the path of a point on a circle as it rolls along the outer side of another circle is called:

a. Epicycloids

b. Cycloid

c. Helical overlap

d. Involute

15. It is the ratio of the arc of action to the circular pitch. For involute gears, it is the ratio of the length of action to the base pitch

a. Pitch ratio

b. Angle ratio

c. Contact ratio

d. Gear ratio

16. Tool bit in lathe machine operation is the same setting ____ degree/angle with horizontal to have good cutting operation position

a. 30 deg

b. 55.5 deg

c. 16.5 deg

d. 20 deg

17. A machine is to be equipped with a cast-iron flywheel 6-ft in diameter and 12-in wide. The arms and hub of the flywheel are considered to be 5% of the rim weight concentrated at the mean diameter. The change in energy to be handled is 2500 ft-lb, and the coefficient of fluctuation is to be 0.04. The running speed of the flywheel is 280 rpm. Determine the rim thickness.

a. 0.3685”

b. 0.4551”

c. 0.2897”

d. 0.5124”

18. A flywheel rim has an inside diameter of 18-in and an outside diameter of 24-in. The weight of the rim is 220 lb. Neglecting any flywheel effect from the arms and hub, determine the radius of gyration, in ft.

a. 0.9101

b. 0.7128

c. 0.8839

d. 0.9019

19. In problem 18, determine the torque required to change the rotational speed from 160 rpm to 220 rpm, in 15 sec.

a. 20.83 lb-in

b. 28.35 lb-in

c. 30.28 lb-in

d. 26.83 lb-in

20. Changing metal from solid to liquid

a. Homogeneity

b. Boiling

c. Recrystalization

d. Melting

21. It is a low cost bearing used world wide for automotive and low horsepower application. It has a thin coating with ____, all over metal chips

a. Babbit

b. Tin

c. Lead

d. Cadmium brass

22. A 1/4-in shaft is subjected to a torsion alone. If the design stress is 5800 psi, how much HP can it transmit if it is rotating at 2200 rpm?

a. 0.6211

b. 0.9981

c. 1.3521

d. 1.8872

23. A steel shaft carrying a pulley and gear is supported by a ball bearings at each end. The following critical speeds have been determined: for the shaft: 110 rad/s, for the pulley: 130 rad/s: for the gear: 125 rad/s. Calculate the critical speed of the system, in rad/sec.

a. 65.2

b. 60.8

c. 69.7

d. 72.1

24. Finding the resultant of two or more forces is called:

a. Couple

b. Composition of forces

c. Non-coplanar

d. Coplanar forces

25. A 12-in long, 1-1/8 inches steel bar is welded between two supports. If the bar is installed at a temperature of 80 deg F, how much stress is induced if the temperature is increased to 145 deg F? The coefficient of expansion for steel is 6.5 x 10^-6

a. 13500 lb/in²

b. 12675 lb/in²

c. 14028 lb/in²

d. 16710 lb/in²

26. A 7-mm steel wire is 5-m long and stretches 8-mm under a given load. If the modulus of elasticity is 180 GPa, what is the applied load?

a. 11083.54 N

b. 10531.22 N

c. 12178.33 N

d. 13821.43 N

27. For mass production of casting. It is generally cheaper to use ____ pattern for longer usage life.

a. Aluminum

b. Wood

c. Metal

d. Brass

28. Determine the capacity of 2.5 ft diameter solid disc flywheel that weighs 320 lbs. The peripheral velocity of the wheel decreases 12% from its rated speed of 65 ft/sec while the machine performing a shearing operation.

a. 2055 ft-lb

b. 2663 ft-lb

c. 2889 ft-lb

d. 2368 ft-lb

29. What force is required to punch a 1.5-in hole in a 3/4-in steel plate? The ultimate shearing stress is 60,000 psi and the ultimate compressive stress is 78,000 psi.

a. 201273 lbs

b. 223121 lbs

c. 212057 lbs

d. 250134 lbs

30. The generally accepted limit for diamond wheel speed should be in the range of ____ fpm.

a. 3000/4000

b. 2500/3500

c. 7000

d. 5000/6000

31. Four compression coil springs in parallel support a load of 900 lbs. Each spring has a gradient of 45 lb/in. How much deflection will result?

a. 5-in

b. 6-in

c. 4-in

d. 7-in

32. A wire rope passes about a driving sheave making an angle of contact of 535 deg. A counterweight of 3350 lb is suspended from one side and the acceleration is 4 ft/sec². If f=0.10, what load may be raised without slipping on the rope?

a. 6530.8 lbs

b. 6638.1 lbs

c. 6793.2 lbs

d. 6922.1 lbs

33. Toolbit, ball peen hammer and calipers are most commonly used tools in ____ shop

a. Machine

b. Forge

c. Foundry

d. Production

34. Calculate the diameter of a wheel rotating at 200 rpm with a rim velocity of 1200 ft/min.

a. 35.7-in

b. 28.1-in

c. 22.9-in

d. 30.8-in

35. A round vertical steel tank has an inside diameter of 3.4 m and 7 m in height. It contains gasoline with a mass density of 530 kg/m³. If the allowable tensile stress is 30 MPa, determine the minimum wall thickness required.

a. 1.25 mm

b. 3.28 mm

c. 2.06 mm

d. 4.81 mm

36. Determine the bursting steam pressure of a steel shell with diameter of 14-in and made of ¼ thick steel plates. The joint efficiency is 80% and the tensile strength is 65 ksi.

a. 3014.3 psi

b. 3812.2 psi

c. 3211.9 psi

d. 3714.3 psi

37. _____ imparts ductility, plasticity or toughness in steel

a. Quenching

b. Tempering

c. Annealing

d. Normalizing

38. Fillet is used in gears to:

a. Increase load factor 

b. Increase tangential force

c. Reduce tensile strength

d. Reduce concentration factor

39. A flywheel speeds up from 320 rpm to 860 rpm in 38 seconds. What is the angular acceleration, in rad/sec²?

a. 2.8

b. 3.4

c. 4.2

d. 1.5

40. _____ is a malleable metal of good oxidation/corrosion resistance. It has also good electrical/magnetic properties

a. Nickel

b. Titanium

c. Copper

d. Aluminum

41. A 2.8-in diameter short shaft carrying pulleys close to the bearings transmits _____ HP when the shaft makes 300 rpm.

a. 160.3

b. 152.3

c. 173.3

d. 180.1

42. Calculate the polar section modulus, in in3 of a triangular shaft whose side is 4-in.

a. 1.3

b. 3.2

c. 2.8

d. 4.1

43. A flange coupling is designed to transmit 27.5 kW at 450 rpm. There are 4-bolts on a 120 mm bolt circle. If the design shearing stress of the bolt is 15 MPa, what is the diameter of bolts should be used to the nearest mm?

a. 10.2 mm

b. 16.1 mm

c. 12.8 mm

d. 14.4 mm

44. A steel shaft 1.50-in in diameter transmits 50 HP at 1300 rpm. Assuming a modulus of rigidity of 12.3 x 106 psi, find the torsional deflection of the shaft in degrees per foot length.

a. 0.2726

b. 0.3531

c. 0.4427

d. 0.5017

45. A line shaft runs at 480 rpm. A 45 cm pulley on the same shaft is belt connected to a 20 cm pulley on the countershaft. From a 30 cm pulley on the countershaft, motion is transmitted to the machine. Calculate the required diameter of the pulley on the machine to give a spindle speed of 600 rpm.

a. 50 cm

b. 48 cm

c. 58 cm

d. 54 cm

46. Find the horsepower delivered by a 40 mm diameter short shaft at 20 rad/s.

a. 15.3

b. 22.1

c. 19.6

d. 18.2

47. _____ fire involving energized electrical equipment

a. Class A

b. Class C

c. Class B

d. Class D

48. ____ is a less expensive bearing for light loads

a. Roller bearing

b. Ball bearing

c. Babbitized

d. Thrust bearing

49. Calculate the nominal shear stress at the surface, in MPa for a 60 mm diameter shaft that is subjected to a torque of 0.50 kN-m.

a. 11.8

b. 12.9

c. 13.8

d. 14.6

50. Maximum number of tooth in a large or driven sprocket

a. 130

b. 132

c. 127

d. 143

51. Should two equal and opposite collinear forces added to the forces already in equilibrium, which of the following statements are true?

a. It increases an unbalanced 

b. Unbalanced of moment is maintained

c. Equilibrium is distributed

d. Equilibrium is maintained

52. What type of hear used for high speed ratio or used for speed reducer?

a. Worm gear

b. Bevel gear

c. Spur gear

d. Helical gear

53. A kind of thread that is generally used

a. UNEC

b. UNC

c. UNF

d. UNEF

54. ____ chain is an assembly of link and joints

a. Sprocket

b. Static

c. Dynamic

d. Kinematic

55. Calculate the diameter of a solid shaft transmitting 80 HP at 1900 rpm. The nature of the load and the type of service is such that the allowable shearing stress on pure torsion is 6500 psi.

a. 1-5/18”

b. 2-1/4”

c. 1-1/2”

d. 1-1/6”

56. A keyed gear delivers a torque of 1300 N-m thru its shaft of 65 mm outside diameter. If the key has thickness of 15 mm and width of 13 mm, find the length of the key. Assume the permissible stress values of 60 MPa for shear and 95 MPa for tension.

a. 48.32 mm

b. 58.21 mm

c. 56.14 mm

d. 51.28 mm

57. The torsional deflection of a shaft is 0.8o in a length of 70 cm. The shear stress is 75 MPa. Compute the diameter of the shaft, in mm. Steel modulus of elasticity is 75 GPa.

a. 90

b.110

c. 120

d.100

58. A 12 m length shaft is used to transmit 60 kW power at 480 rpm. If the shaft stress is limited to 45 MPa, determine the angular deflection of the steel shaft, in degrees.

a. 15

b. 18

c. 12

d. 10

59. Find the stress developed by the 30 mm diameter shaft that is used to transmit 25 kW of power at 720 rpm.

a. 68213 kPa

b. 72381 kPa

c. 62549 kPa

d.64222 kPa

60. A motor is used to drive a centrifugal pump that discharges 2800 L/min at a head of 14 m. The pump efficiency is 70% and running at 620 rpm. Calculate the torsional stress of the shaft if shaft diameter is 38 mm.

a. 10 MPa

b. 12 MPa

c. 11 MPa

d. 13 MPa

61. A 15 m cantilever beam has a concentrated load of 30 kN at the mid-span. Find the maximum slope of the beam (EI=10,000 kN-m²)

a. 0.0844 rad

b. 0.1201 rad

c. 0.0192 rad

d. 0.1881 rad

62. Color code for steam pipe:

a. Silver-gray

b. White

c. Clear

d. Brown

63. Consider a maximum safe center distance of sprocket should be ____ pitches. Very long center distance cause catenary tension in the chain

a. 60

b. 80

c. 50

d. 70

64. Poisson’s ratio is the ratio of

a. Lateral deformation to the longitudinal deformation 

b. Elastic limit to yield strength

c. Elastic limit to shear strength

d. Shear strain to unit strain

65. A 15 m simply supported beam has a uniform load of 4 kN/m from left end to the right end and concentrated load of 16 kN at the center has a maximum deflection of _____ mm. (EI = 12000 kN-m²)

a. 300.40

b. 391.21

c. 313.45

d. 330.18

66. A 10 m simply supported beam with uniform load of 2.8 kN/m from right end to the left end has a maximum deflection of ____ mm. (EI = 7200 kN-m²)

a. 40.21 mm

b. 50.11 mm

c. 45.21 mm

d. 47.34 mm

67. A horizontal cantilever beam, 25 ft long is subjected to a load of 5500 lb located to its center. The dimension of the beam is 9 x 12-in, respectively. w = 130 lb/ft, find its flexural stress.

a. 5039 psi

b. 5729 psi

c. 4831 psi d

. 4531 psi

68. Two parallel shafts have an angular velocity ratio of 4 to 1, are connected by gears. The largest of which have 56 teeth. Find the number of teeth of the smaller gear.

a. 12

b. 13

c. 14

d. 15

69. A clutch has an outside diameter of 9-in and inside diameter of 4.5-in. An axial force of 520 lb is used to hold the two parts together. If the friction is 0.38, how much torque can the clutch handle?

a. 671.3 lb-in

b. 691.6 lb-in

c. 655.1 lb-in

d. 643.8 lb-in

70. How much torque can a cone clutch transmit if the angle of the conical element is 12 degrees and the mean diameter of conical section is 230 mm and an axial force of 650 N is applied? Consider a coefficient of friction of 0.40.

a. 143.8 N-m

b. 155.3 N-m

c. 138.2 N-m

d. 166.1 N-m

71. Cutting fluids used for reaming, drilling and tapping hard spot of cast iron

a. Turpentine

b. Dry

c. Kerosene

d. Soda water

72. All are stainless steel in AISI specification except:

a. 92xx

b. 515xx

c. 302xx

d. 304xx

73. Which of the following is not operated in excess of 6000 fpm?

a. Flat leather belt

b. Worm gear

c. Herringbone

d. V-belt

74. A cone clutch has an angle of 11 degrees and coefficient of friction of 0.39. Find the axial force required of the capacity of the clutch is 10 kW at 550 rpm. The mean diameter of the active conical section is 300 mm. Use uniform wear method.

a. 566.2 N

b. 500.0 N

c. 531.8 N

d. 589.1 N

75. The commonly used tool to measure the diameter in machine shop operation but usually used with steel scale for measurement

a. Caliper

b. Vernier

c. Micrometer

d. Protractor

76. A steel band has a maximum tensile stress of 60 MPa and thickness of 5 mm. If the tension in tight side is 8 kN, what width of band should be used?

a. 26.67 mm

b. 32.11 mm

c. 42.10 mm

d. 49.21 mm

77. On a brake drum the difference in tension between slack side and tight side is 5 kN. If the ratio of band tension is 4, determine the tension in tight side.

a. 6.7 kN

b. 7.8 kN

c. 8.1 kN

d. 5.3 kN

78. In a brake, the tension on tight side is thrice of the slack side. If the coefficient of friction is 0.30, find the angle of contact of the band, in deg.

a. 209.8

b. 220.4

c. 231.1

d. 253.8

79. A brake has a difference on band tension of 5 kN. The drum diameter is 1.2 m and rotating at 320 rpm. Determine the power required to drive the drum.

a. 100.5 kW

b. 120.0 kW

c. 113.3 kW

d. 142.8 kW

80. A chain and sprocket has a pitch diameter of 28.654-in and there are 90 teeth available, find the pitch of the chain.

a. 1”

b. 1.5”

c. 2”

d. 2.5”

81. A chain and sprocket has a pitch diameter of 9.56-in and a pitch of ½-in, how many teeth are there in the sprocket?

a. 55

b. 65

c. 60

d. 50

82. A chain and sprocket has 24 teeth with a chain pitch of ¾-in. If the sprocket turns at 620 rpm, find the speed of the chain.

a. 900 fpm

b. 950 fpm

c. 930 fpm

d. 910 fpm

83. A chain and sprocket has 20 teeth with a chain pitch of ½-in, find the diameter of the sprocket.

a. 2.8-in

b. 4.8-in

c. 3.2-in

d. 5.0-in

84. A bearing has a per unit load of 600 kPa. The load on bearing is 30 kN and it has a diametral ratio of 0.0013. If the diameteral clearance is 0.130 mm, find the length of the journal required.

a. 300 mm

b. 350 mm

c. 400 mm

d. 500

85. A bearing journal rotates at 480 rpm is used to support a load of 60 kN. It has a diameter of 22 cm and length of 38 cm. Find the friction loss, in kW per bearing. Use f=0.11.

a. 18.2

b. 20.1

c. 24.9

d. 28.3

86. A bearing 160 mm diameter and 320 mm long supports a load of 4800 kg. If the coefficient of friction is 0.20, find the torque required to rotate the shaft.

a. 350.2 N-m

b. 376.7 N-m

c. 382.8 N-m

d. 330.2 N-m

87. The main bearings of a one cylinder steam are 155 mm diameter by 290 mm long and support a load of 4500 kg. Find the bearing stress.

a. 403.51 kPa

b. 462.33 kPa

c. 493.54 kPa

d. 433.11 kPa

88. In general, many cases happen in the incorrect position of filing. The correct position of filing in general in the lathe machine is ____ hand.

a. Any position

b. Right

c. Center

d. Left

89. Gates and risers are terms used in

a. Foundry

b. Boilers

c. Pitting

d. Gears

90. Acceleration is proportional to the force

a. Newton’s Law

b. Pascal’s Law

c. Archimedes Law

d. Boyle’s Law

91. Dynamic seals are also known as

a. Packings

b. Space rings

c. Spring key

d. Washers

92. Find the distance between centers of a pair of gears, one of which has 14 teeth and the other 38 teeth. The diametral pitch is 8.

a. 2.21-in

b. 3.25-in

c. 4.28-in

d. 5.75-in

93. Compute the speed of the gear mounted in a 55 mm diameter shaft receiving power from a prime motor with 300 HP.

a. 2000.8 rpm

b. 2363.9 rpm

c. 3501.8 rpm

d. 3008.1 rom

94. A gear set having a gear ratio of 4 is to be used at a center distance of 12-in. If the gear has 64 teeth, what must be the circular pitch.

a. 0.9425

b. 0.8121

c. 0.7312

d. 0.6311

95. Compute for the working strength of 1-½ inch bolt which is screwed tightly in packaged joint when the allowable stress is 14,000 psi.

a. 5621.8 lb

b. 4278.8 lb

c. 3213.5 lb

d. 4599.1 lb

96. Find the tooth thickness of a 14.5 deg involute gear having diameteral pitch of 8.

a. 3.5 mm

b. 4.0 mm

c. 5.0 mm

d. 6.5 mm

97. Type of bevel gear with variable angle of contact and slope.

a. Angular

b. Annular

c. Horizontal

d. Hypoid

98. Basic size is the same as design size if there is no

a. Balance

b. Clearance

c. Distance

d. Allowance

99. Ability of a material to absorb strain energy and will result to its original state

a. Resilience

b. Hardenability

c. Elasticity

d. Machinability

100. Job in which Mechanical Engineer is not permitted to do.

a. To maintain a 2000 kW generator 

b. To sign plans, specifications, design etc.

c. To operate 1800 kW machines

d. To operate 500 kW machines

Answer Key (Handwritten)