Bhavini sa b mechanical question paper

7. Dec 2017
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Bhavini sa b mechanical question paper

• 1. Page 1 of 8 QUESTION PAPER- SA/B (MECHANICAL ENGG) -2009 TEST DURATION: 2 HRS MAX. MARKS: 100 (Questions 1 to 40 carry 2 marks each and questions 41 to 60 carry 1 mark each.) 1. A piece of ice floats in a jar of water. What will happen to the level of water when all the ice melts? (A) Water level increases (B) Water level decreases (C) Water level remains constant (D) Water level first decreases, then increases. 2. A piece of wood of uniform area of cross section sinks to a depth of 10 cm in a liquid and 12 cm in water. What is the specific gravity of the liquid? (A) 1.5 (B) 0.83 (C) 0.75 (D) 1.2 3. A flat bottom vessel filled with lead shots floats in a jar of water. All the lead shots inside the vessel are now put into the water. What will happen to the level of water in the jar? (Note: Density of Lead is much greater than the density of water) (A) Level remains same (B) Level increases (C) Level decreases (D) None of the above 4. Weightlessness is observed by the astronaut in which of the following cases? (A) During free fall towards the earth in an enclosed capsule. (B) During orbital motion around the earth in a space shuttle. (C) In both (A) & (B) above. (D) None of the above. 5. At what height from the earth’s surface will a body have one fourth of its weight on the surface of the earth (A) At a height equal to half the radius of earth (B) At a height equal to one fourth the radius of the earth (C) At a height equal to twice the radius of the earth (D) At a height equal to the radius of the earth 6. When the length of a simple pendulum is doubled, its time period of oscillation is (A) Doubled (B) Halved (C) Becomes 1 /√2 times (D) Becomes √2 times 7. In a vernier caliper, 12 mm on the main scale is equal to 25 divisions on the vernier scale. If one main scale division is equal to 0.5 mm, what is the least count of the vernier? (A) 0.01 mm (B) 0.015 mm (C) 0.025 (D) 0.02 mm 8. In a centrifugal pump, conversion of kinetic energy of the fluid to pressure energy of the fluid occurs in the (A) Impeller (B) Diffuser/Volute casing (C) Discharge line (D) None of the above 9. When the speed of a pump is doubled, the discharge through the pump
• 2. Page 2 of 8 (A) Increases four times (B) Increases √2 times (C) Increases 2 times (D) Remains constant. 10. The function of safety relief valve is to (A)Shut down the piping system during emergency conditions. (B) Remove unwanted gases from the piping system. (C) Protect the vessel / piping against overpressure by releasing the excess fluid to the atmosphere (D)None of the above. 11. Which of the following valves is used for regulating the flow of fluid through a pipeline? (A) Gate valve (B) Ball valve (C) Check valve (D) Globe valve 12. Which of the following valves allow passage of fluid with minimum disturbance to the flow? (A) Butterfly valve (B) Ball valve (C) Globe valve (D) Plug valve 13. The volume of a gas is 600 cm³ at 27ºC. What will be the volume when the temperature is increased to 127ºC while the pressure is kept constant? (A) 2822 cm³ (B) 800 cm³ (C) 1000 cm³ (D) 1285 cm³ 14. At a pressure of 300 bar and 400ºC, water exists as (A) Liquid phase (B) Wet steam (C) Super heated steam (D) Super critical state 15. Sea water as compared to distilled water will boil at (A)Same temperature (B) Higher temperature (C) Lower temperature (D)Higher or lower depending on PH value 16. ‘Critical Temperature’ of a fluid refers to which one of the following? (A) It is the temperature at which conversion from liquid state to gaseous state occurs. (B) It is the temperature at which conversion from solid state to gaseous state occurs. (C) It is the temperature above which a gas cannot be liquefied by the application of pressure (D) It is the temperature at which all the three phases (solid/liquid/gas) are in equilibrium. 17. With decrease in atmosphere pressure (A) Boiling point increases (B) Boiling point decreases (C) Boiling point remains the same (D) Melting point decreases 18. Combined cycle power plants adopt a mixture of
• 3. Page 3 of 8 (A) Brayton cycle & Ericsson cycle (B) Brayton cycle & Rankine cycle (C) Ericsson cycle & Rankine cycle (D) Stirling cycle & Ericsson cycle 19. In a reaction type steam turbine (A) Pressure and velocity decreases in the moving blades (B) Only pressure reduction takes place (C) Only velocity reduction takes place (D) None of the above 20. Which of the following equipment is used to create high vacuum in vessels/ condensers without any mechanical force input? (A) Reciprocating compressor (B) Sliding vane compressor (C) Lobe type compressor (D) Steam jet air ejector 21. The most efficient method of compressing air is to compress it (A) Isothermally (B) Adiabatically (C) Isentropically (D) Isochorically 22. A Compressor at high altitude will draw (A) Less Power (B) More Power (C) Same Power (D) More/Less Power depending upon other factors 23. Which of the following is the biggest quantum of pressure (A) 1 kg/cm2 (B) 1 inch of mercury (C) 1 m of water column (D) 1 pound/sq inch 24. In a cylindrical vessel subjected to internal pressure, the ratio of stresses induced in the longitudinal seam joint to that induced in circumferential seam joint are in the ratio: (A) 2 : 1 (B) 1 : 2 (C) 4 : 1 (D) 1 : 4 25. The efficiency of a screw jack is given by which of the following (α = Helix angle, φ = Angle of friction) (A) tan (α + φ) / tan α (B) tan α / tan (α + φ) (C) tan (α - φ) / tan α (D) tan α / tan (α - φ) 26. Which of the following roller bearings can tolerate slight angular misalignment? (A) Cylindrical roller bearings (B) Spherical roller bearings (C) Needle roller bearings (D) Tapered roller bearings. 27. The maximum shear stress in beams generally occurs at
• 4. Page 4 of 8 (A)Top (B) Bottom (C) Centroid (D) Neutral Axis 28. The rotational speed of a 6 pole squirrel cage induction motor operating at 50 HZ frequency is nearest to (A) 3000 rpm (B) 1500 rpm (C) 1000 rpm (D) 750 rpm 29. Alloy steels are usually made by which of the following processes? (A) Open hearth process (B) Bessemer converter (C) Crucible process (D) Electric arc furnace 30. Solid solution of carbon in iron is called (A) Austenite (B) Martensite (C) Pearlite (D) Ferrite 31. One of the principle duties of the steam condenser in a thermal power plant is to (A) Create the lowest possible turbine operating back pressure. (B) Cool the steam turbine. (C) Regulate power output of the turbine. (D) Maintain constant rate of flow of steam through the turbine. 32. In an SI engine the Ignition Distributor gets its drive from the (A) Crankshaft (B) Camshaft (C) Separate timing gear (D) Fuel pump 33. ‘A’ does a particular work alone in 10 days and ‘B’ does the same work alone in 15 days. How many days would they take do the same work, if they work together? (A) 5 days (B) 6 days (C) 8 days (D) 9 days 34. A train 100 metres long takes 6 seconds to cross a man walking at 5 Kmph in a direction opposite to that of the train. Find the speed of the train. (A) 55 Kmph (B) 58 Kmph (C) 70 Kmph (D) 85 Kmph 35. A bar of uniform cross section and homogeneous material weighing 1000N and having cross section of 1 cm² and length 1m hangs vertically while suspended from one end. Value of E = 10,000 N/mm². The extension of the bar due to its own weight will be (A) 1 mm (B) 0.5 mm (C) 2 mm (D) 0.25 mm 36. For a given material, the modulus of rigidity is 10000 N/mm² and poisson ratio is 0.25. The value of modulus of elasticity will be (A) 2000 N/mm² (B) 12,500 N/mm² (C) 15000 N/mm² (D) 25000 N/mm² 37. In the case of a beam supported at both ends, if the same load instead of being concentrated at the centre is distributed uniformly throughout the length, then the deflection in the centre will get reduced by (A) ½ (B) ¼ (C) ¾ (D) 5 /8
• 5. Page 5 of 8 38. A jet of water issuing out from a nozzle with a velocity of 12 m/s is suddenly stopped by a wall. If the flow rate of water from the outlet of the nozzle is 5000 cm3 /s, what is the force exerted by the jet of water on the wall? Density of water is 1gram/cm3 . (A) 22.5N (B) 30N (C) 60N (D) 45N 39. A load of 4000 N has to be raised at the end of a steel wire. If the unit stress in the wire must not exceed 80 N/mm². What will be the extension of 3.5 m length of wire? Take E = 200000 N/mm². (A) 1.8 mm (B) 1.4 mm (C) 2 mm (D) 1.6 mm 40. Find the Centroid of the lamina shown in figure with respect to its bottom edge. (A) 40 mm (B) 54 mm (C) 28 mm (D) 34mm 41. The maximum stress which a material can withstand before plastic flow sets in is known as (A) Yield strength (B) Allowable tensile strength (C) Ultimate tensile strength (D) Breaking stress 42. Density of water is maximum at (A) 0ºC (B) 4ºC (C) 20ºC (D) 96ºC 43. Which of the following bearing materials are used for high speed shafts of large diameters due to its ability to adapt itself more closely to the shape of the shaft? (A) Bronze (B) Babbit (C) Chrome steel (D) Brass 44. When r = base radius and h = height, curved surface area of a cone is equal to: (A) rh (B) r√( r² + h²) (C) r √ (h ² - r ²) (D) r √ (r² - h ²) 45. The material which exhibits same elastic properties in all directions is known as (A) Homogeneous material (B) Isotonic material (C) Isotropic material (D) Isentropic material 100mm 20mm 150mm 20mm
• 6. Page 6 of 8 46. In a screw gauge, while measurement of diameter of a wire sample, 7.5 mm of the barrel scale is uncovered and the thimble scale coincidence is 33. What is the diameter of the wire sample? (A) 7.83 mm (B) 7.17 mm (C) 7.67 mm (D) 6.84 mm 47. Which of the following machines does not require a flywheel? (A) Reciprocating compressor (B) Four stroke diesel engine (C) Reciprocating pump (D) Steam turbine 48. In an economizer of a boiler (A) Latent heating of feed water occurs. (B) Sensible heating of feed water occurs (C) Super heating of steam occurs (D) Sensible heating of steam occurs 49. ‘Caustic Embrittlement’ is a phenomenon observed in (A) Steam boilers (B) Condensers (C) Steam turbines (D) Boiler feed water pump 50. Which of the following welding process utilizes powdered flux which melts and covers the arc during welding? (A) SMAW (B) GTAW (C) SAW (D) GMAW 51. Which of the following operation is used to give good finish and accuracy to a drilled hole? (A) Boring (B) Reaming (C) Counter boring (D) Counter sinking 52. Which of the following gears is used for transmitting power at high velocity ratios between non- intersecting shafts? (A) Bevel gear (B) Spur gear (C) Worm gear (D) Helical gear 53. The most commonly used firing order in a four stroke six cylinder I. C. Engine is (A) 1-3-6-5-2-4 (B) 1-4-2-5-6-3 (C) 1-5-3-6-2-4 (D) 1-5-2-6-3-4 54. Falling drops of water become spheres due to (A) Adhesion (B) Cohesion (C) Surface Tension (D) Viscosity 55. Steel balls are manufactured by (A) Casting (B) Machining (C) Cold Heading (D) Sintering 56. The Combination Set is used to (A) Check angular surfaces (B) Draw circles and arcs (C) Scribe lines (D) All of the above
• 7. Page 7 of 8 57. Notched bar tests are frequently used for testing the (A) Impact strength of a material (B) Hardness of a material (C) Machinability of a material (D)Corrosion resistance of the material 58. The Rockwell number refers to a materials (A) Malleability (B) Toughness (C) Plasticity (D) Hardness 59. A Steam Nozzle converts (A) Kinetic Energy into Heat Energy (B) Heat Energy into Potential Energy (C) Potential Energy into Heat Energy (D) Heat Energy into Kinetic Energy 60. Second law of thermodynamics defines the concept of (A) Entropy (B) Enthalpy (C) Heat (D) Work Question No Answer Question No Answer Question No Answer 1 C 21 A 41 A 2 D 22 A 42 B 3 C 23 A 43 B 4 C 24 A 44 B 5 D 25 B 45 C 6 D 26 B 46 A 7 D 27 D 47 D 8 B 28 C 48 B 9 C 29 D 49 A 10 C 30 A 50 C 11 D 31 A 51 B
• 8. Page 8 of 8 12 B 32 B 52 C 13 B 33 B 53 C 14 D 34 A 54 C 15 B 35 B 55 C 16 C 36 D 56 D 17 B 37 D 57 A 18 B 38 C 58 D 19 A 39 B 59 D 20 D 40 D 60 A