QP-EnggServcPrelExam-24-MECHANICAL-ENGINEERING-190224

Engineering Services (P) Examination, 2024 DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO T.B.C. : PNGE-D-MCH Test Booklet Series Serial No. 1011769 TEST BOOKLET Paper—IlI ( MECHANICAL ENGINEERING ) Time Allowed : Three Hours Maximum Marks : 300 INSTRUCTIONS 1. IMMEDIATELY AFTER THE COMMENCEMENT OF THE EXAMINATION, YOU SHOULD CHECK THAT THIS TEST BOOKLET DOES NOT HAVE ANY UNPRINTED OR TORN OR MISSING PAGES OR ITEMS, ETC. IF SO, GET IT REPLACED BY A COMPLETE TEST BOOKLET. 2. Please note that it is the candidate’s responsibility to encode and fill in the Roll Number and Test Booklet Series A, B, C or D carefully and without any omission or discrepancy at the appropriate places in the OMR Answer Sheet. Any omission/discrepancy will render the Answer Sheet liable for rejection. 3. You have to enter your Roll Number on the Test Booklet in the Box provided alongside. DO NOT write anything else on the Test Booklet. 4. This Test Booklet contains 150 items (questions). Each item comprises four responses (answers). You will select the response which you want to mark on the Answer Sheet. In case you feel that there is more than one correct response, mark the response which you consider the best. In any case, choose ONLY ONE response for each item. 5. You have to mark your responses ONLY on the separate Answer Sheet provided. See directions in the Answer Sheet. 6. All items carry equal marks. 7. Before you proceed to mark in the Answer Sheet the response to various items in the Test Booklet, you have to fill in some particulars in the Answer Sheet as per instructions sent to you with your Admission Certificate. 8. After you have completed filling in all your responses on the Answer Sheet and the examination has concluded, you should hand over to the Invigilator only the Answer Sheet. You are permitted to take away with you the Test Booklet. 9. Sheets for rough work are appended in the Test Booklet at the end. 10. Penalty for wrong answers : THERE WILL BE PENALTY FOR WRONG ANSWERS MARKED BY A CANDIDATE. (i) There are four alternatives for the answer to every question. For each question for which a wrong answer has been given by the candidate, one-third of the marks assigned to that question will be deducted as penalty. (ii) If a candidate gives more than one answer, it will be treated as a wrong answer even if one of the given answers happens to be correct and there will be same penalty as above to that question. (iii) If a question is left blank, i.e., no answer is given by the candidate, there will be no penalty for that question. DO NOT OPEN THIS TEST BOOKLET UNTIL YOU ARE TOLD TO DO SO 1. Consider the following statements : 3. Two horizontal plates are placed 1:25 cm apart, the space between them being filled with an oil of viscosity 15 poises. increase in temperature. What is the shear stress in the oil if the upper plate is moved with a velocity of 2:5 m/s? 1. Viscosity of liquid increases with 2. Viscosity of gas decreases with increase in temperature. ୭, এ} liquids, cohesive forces ਹੇ predominate the molecular (2) 280 N/m momentum transfer. 4. In gases, cohesive forces are small (b) 260 ೫ /m? and the molecular momentum transfer predominates. (c) 300 N/m? Which of the above statements are correct? (0 250 N/m? (a) 1 and 2 only (b) 2 and 3 only ‎tube‏ 6ئ ‎tind 4 tity 4. What is the capillary) rise ina‏ ات زم ‎of 2:0mm diameter when immersed‏ ‎vertically in mercury? (Take surface‏ ‎tension of mercury as 0:52 N/m. The‏ ‎specific gravity of mercury is 13۰6 and‏ ‎the angle of contact is 130°)‏ ‎(0) 1, 2, 3 and 4 ‎2. A fluid in which shear stress is more than the yield value and shear stress is proportional to the rate of shear strain ‎८) -0:25 cm is known as (a) (a) non-ideal plastic fluid ‏رم‎ -065 cm (b) Newtonian fluid ‎(જ -08 cm (c) non-Newtonian fluid (0) ideal plastic fluid (व) -05 cm ‎PNGE-D-MCH/52A 2 5. Consider the following statements : 1. One end of piezometer is connected to the point where pressure is to be measured and the other end is open to the atmosphere. 2. Inverted U-tube differential manometer is used to measure high pressure. 3. U-tube differential manometer contains heavy liquid. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (ध) 1, 2 and3 6. A circular opening, 3m diameter, in a vertical side of a tank is closed by a disc of 3 m diameter which can rotate about a horizontal diameter. What is the force on the disc if the head of water above the horizontal diameter is 5 m? (a) 277-4kN நு 3244 KN (౧ 311:2kN (0) 3467 KN PNGE-D-MCH/52A 7. Consider the following statements regarding dynamics of fluid flow : 1. Pitot tube is a device used to measure rate of flow of fluid through a pipe. 2. Orifice meter is a device used for measuring velocity of flow at any point in a pipe. 3. Venturi meter consists of converging part, throat and diverging part. Which of the above statements is/are correct? (a) 1 and 3 (b) 2 only (c) 3 only (d) 1 and 2 8. What is the pressure gradient per metre width for the laminar flow of oil with a maximum velocity of 2 m/s between two horizontal parallel fixed plates which are 100mm apart? (Take dynamic viscosity = 2:5 N-s/m?) (જ -4000 N/m? per m (b) -3700 N/m? per m (c) -3500 N/m? per m (0 -3200 N/m? per m [ P.7.0. 9. Consider the following statements regarding dynamics of fluid flow : 1. Kinetic energy correction factor is defined as the ratio of kinetic energy of the flow per second based on actual velocity to kinetic energy of the flow per second based on average velocity. 2. Kinetic energy correction factor is defined as the ratio of kinetic energy of the flow per second based on average velocity ୮୦ kinetic energy of the flow per second based on maximum velocity. ૩. Momentum correction factor is defined as the ratio of momentum of the flow. per second based on actual velocity to momentum of the flow per second based on average velocity. 4. Momentum correction factor is defined as the ratio of momentum of the flow per second based on average velocity to momentum of the flow per second based on maximum velocity. Which of the above statements are correct? (a) 1 and 4 (b) 1 and 3 (c) 2 and 4 (0) 2 and3 PNGE-D-MCH/52A 10. An oil is flowing through a pipe of diameter 300mm with velocity of 5 0/5. What is the head loss to maintain the flow for a length of 1000 m? (Take coefficient of friction = 0-005) (a) 602 ௩ (b) 724 ௩ (८ 76:7 प (0) 849 m 11. Consider the following statements : 1. The apparent viscosity of a pseudoplastic fluid decreases with decrease in the shear rate. 2. The apparent viscosity of a dilatant fluid increases with increase in the shear rate. 3. Bingham plastic fluid requires a finite yield stress before beginning to flow. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and3 12. The dimensional formula of bulk modulus of elasticity in MLT notation system is (0 22771 മു 271772 () 171771 (a) 177172 13. Consider the following statements regarding general conventions in stress analysis : 1. Tensile stress is positive and compressive stress is negative. 2. A pair of shear stresses on parallel planes forming a clockwise couple is positive and a pair with a counterclockwise couple is negative. 3. Clockwise angle is taken as negative and _ counterclockwise couple is positive. Which of the above statements are correct? (a) 1 and 2 only (0) 1 ஹல்‌ 3 only (c) 2 and 3 only (0 1, 2 and 3 14. Consider the following statements regarding principle of superposition : 1. The principle of superposition States that if a body is acted upon by a number of loads on various segments of the body, then the net effect on the body is the sum of the effects caused by each of the loads acting independently ୦୮ the respective segment of the body. PNGE-D-MCH/52A 2. The superposition principle applies to all parameters like stress, strain and deflection. 3. The superposition principle 15 applicable to materials with non-linear stress-strain charac- teristic, which do not follow Hooke’s law. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 15. Rails are laid such that they have no stress at 24°C. What is the stress in the rails at 80°C, when there is no allowance for expansion? (Assume coefficient of linear expansion = 11× 10-6 °c"! and Young’s modulus of rails metal = 205 GPa) (2) 126:28 MPa (b) 251-84 MPa (c) 296-72 MPa (0 32535 MPa (೫.7.೦. 16. When a body is acted upon by pure shear stresses on two perpendicular planes, the planes inclined at 45° are subjected to (a) a tensile stress of magnitude equal to that of the shear stress (b) a compressive stress of magnitude equal to that of the shear stress (c) a torsional stress of magnitude equal to that of the shear stress (0) a bending stress of magnitude equal to that of the shear stress 17. A piece of material is subjected to same two perpendicular tensile stresses of 100 MPa each. What is the direct stress? (a) 90 MPa (b) 100 MPa (c) 96 MPa (0) 86 MPa 18. The strain energy per unit volume required to cause the material to rupture is called (a) modulus of toughness (b) modulus of rigidity (© resilience (97 proof resilience PNGE-D-MCH/52A 19. Consider the following statements regarding buckling concept : 1. Buckling can occur when the induced stresses are compressive such as in a column. 2. Buckling analysis ৮৪০৪ the Young’s modulus of the material and the moment of inertia of the column cross-section, as well as its length. ૩. The load that buckles the column is called the crushing load. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 20. Consider the following statements regarding theories of failures : 1. Maximum principal strain theory is known as St. Venant’s theory. 2. Maximum shear strain energy theory is known as Mises and Hencky theory. 3. Maximum strain energy theory is known as Guest and Tresca theory. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 and 3 21. Consider the following statements regarding beams : 1. Beams with one end fixed and the other end simply supported are known as propped cantilevers. 2. Beams supported at more than two sections are known as fixed beams. 3. Beams with one end fixed and the other end free are known as cantilevers. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 22. Consider the following statements regarding effective length of a column : 1. The effective length is the distance between the points of inflection in the deformed shape of the column, which is referred to as the elastic curve. 2. At the inflection point, the moment does not change sign and the member is not expected to resist any moment. 3. At the transition point, the curvature is changed and it is called the contraflexure point. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 PNGE-D-MCH/52A Consider the following statements regarding power transmitted through a circular shaft : 1. 116 stress ஹம்‌ deformation induced in the shaft can be calculated by relating power to torque. 2. The power produced by a motor is rated in terms of shaft horsepower at a specified rotational speed. 3. Power is defined as the work done per unit time. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 24. When a body is acted upon by pure shear stresses on two perpendicular planes, the planes inclined at 135° are subjected to (a) a tensile stress of same magnitude with no shear stress on these planes (b) a compressive stress of same magnitude with no shear stress on these planes (c) ৪ torsional stress of same magnitude with no shear stress on these planes (0) 8 bending stress of same magnitude with no shear stress on these planes [छः 25. Which one of the following is the ability of a material to regain its original shape on removal of the applied load? (a) Proof resilience (b) Resilience (c) Modulus of resilience (व) Gradual resilience 26. Which one of the following properties is not an extensive property of a system? (a) Energy (0) Enthalpy (c) Volume (0) Temperature 27. Two cylindrical vessels of 2 103 each are inter-connected through a pipe with a valve in-between. Initially, the valve is closed and one vessel has 20 kg air while 4kg of air is there in second vessel. Assuming the system to be at 27 °C temperature initially and perfectly insulated, what is the final pressure in vessels after the valve is opened to attain equilibrium? (a) 516:6 kPa (b) 51:66 kPa (જ 5616 kPa (0 56:16 kPa PNGE-D-MCH/52A 28. Thermoelectric thermometer works on the principle of (a) Wheatstone bridge (b) entropy (c) Seebeck effect (d) ohmmeter 29. Isentropic expansion expressed as efficiency is (a) Ideal work in expansion - Actual work in expansion (b) Actual work in expansion + Ideal work in expansion (0) Ideal work in expansion Actual work in expansion ‎Actual work in expansion‏ رم ‎Ideal work in expansion ‎30. In the reheat cycle, the principal advantage of reheat is to increase the quality of steam at ‎(a) turbine exhaust (b) turbine inlet (c) feed pump inlet ‎(0) feed pump exhaust 31. Consider that the Rankine cycle 33. The equation for two-dimensional efficiency is improved in the following steady-state conduction without heat ways : sources is 1 ition 1 il 6317 q 1. By reducing heat addition in boiler (a) र ৷; মি 0 Ir 2. By increasing steam _ turbine ந்‌) ৫2171 ૮7 expansion work ಡೌ कक 7 3. 3) reducing feed pump work (0) 6317 2 ax? = Which of the above are correct? ರ (व) —~+—>=0 ax? 2४ (a) 1 and 2 only 34. Which one of the following expressions is correct about the relation among Grashof number (Gr), Prandtl number (Pr) and Rayleigh number (Ra)? (a) Ra = ೧೯೫: (b) 2 and 3 only (c) 1 and 3 only (b) Gr = RaPr જિ Ra = Gr-Pr (0 Gr = Ra-Pr (0) 1, 2 and3 32. What is the actual pressure of air in the tank if the pressure of compressed air 35. An order-of-magnitude analysis of the measured by manometer is 30cm of mercury and atmospheric pressure is 101kPa? (Take g=9-78m/s? and density of mercury at room temperature as 13550 kg /೫73) (a) 14076 GPa (0) 14076 MPa (c) 14076 kPa (0) 140-76 Pa PNGE-D-MCH/52A free convection boundary layer equa- tions will indicate a general criterion for determining whether free convection effects dominate. The criterion is that when (a) Gr/Re? <10, then free convection is of primary importance (b) Gr/Re? = 10, then free convection is of primary importance (c) Gr/Re? >10, then free convection is of primary importance (6) Gr/Re? >10, then forced convec- tion is of primary importance (೫.7.೦. 36. Ifthe monochromatic emissivity of a body 39. Consider the following statements for the is independent of wavelength, it is called characteristics of ionic compounds : 1. Ionic compounds ലട generally (a) transparent body crystalline in nature and rigid. 2. They are generally non-conductors (b) reflective body of electricity. 3. They are insoluble in organic solvents, but highly soluble in water. (c) black body ൽ gray body Which of the above statements are correct? 37. Which one of the following equations is (a) 1 and 2 only called Kirchhoff’s identity? (b) 2 and 3 only ഭട (જ 1 and 3 only Ep (0 1, 2 and 3 = 2⁄8 @ ટજ छ 40. Consider the following statements for the characteristics of covalent compounds : (c) £ = = 1. They can exist in all states of matter. (ಗ) ६1 2. They ലട generally _ electric insulators. 3. They are insoluble in water, but 38. The interface angles of rhombohedral soluble in non-polar solvents such crystal systems are as benzene and alcohol, etc. స్ట Which of the above statements are બાલા ભ ദു; correct? (0) ५ = 6 = # = 90° (a) 1 and 3 only (b) 2 and 3 only (જ a=B=90°ry (c) 1 and 2 only (व) ५ = 8 = 90%; y = 120° (0) 1, 2 and 3 PNGE-D-MCH/52A 10 41. Consider the following statements : 1. X-rays are not deflected by electric or magnetic fields. 2. They produce fluorescence in many substances. 3. They are highly penetrating and destructive on living tissues on excessive exposure. Which of the above statements are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (0 1, 2 and 3 42. Consider the following statements : The application of X-rays in scientific research is 1. to investigate the structure of crystalline solids ‎study complex organic‏ 78و2 ‎compounds by analyzing their‏ ‎structures‏ ‎3. to find the atomic numbers and energy levels to identify the elements ‎Which of the above statements are correct? ‎(a) 1 and 3 only (b) 2 and 3 only (જી 1 and 2 only (0 1, 2 and 3 ‎PNGE-D-MCH/52A ‎11 ‎43. Consider the following statements : ‎The influence of molybdenum element ‎in steels ‎1. imparts strength ‎2. enhances resistance to creep ‎3. minimizes temperature brittleness ‎higher temperature ‎Which of the above statements is/are correct? ‎(a) 1 only ‎(b) 2 and 3 only (c) 1 and 2 only (व) 1, 2 and 3 ‎44. The alloying elements of tungsten-based ‎tool steels are ‎(a) Cr, V, Co and W (b) Cr and V only (c) Cr, Ni and Mo (0 Cr, W, V and Mo ‎45. Consider the following disadvantages of ‎LAUE methods : ‎1. Various reflections may make the appearance of the photograph complicated. ‎2. Due to the wide range of wave- lengths, there is overlapping of diffraction images. ‎3. There is a variation of incident X-ray beam due to the large range of wavelengths. ‎Which of the above disadvantages is/are correct? ‎(a) 1 and 3 only ‎(b) 1 and 2 only ‎(c) 3 only ‎(0 1, 2 and 3 ‎1೫.7.೦. 46. Optical pyrometer works based on the principle of (a) conduction only (b) convection only (c) radiation (0) conduction and convection 47. Consider the following common defects in steel due to heat treatment : 1. Warping 2. Oxidation 3. Quenching cracks Which of the above defects are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (0 1, 2 and3 48. Consider the following conditions to be fulfilled before a powder metallurgy product can be made : 1. It must be possible to form a continuously bonded matrix. 2. The metal in the powder form must be able to respond to solid phase welding. 3. The powders in which the basic materials are available must be sufficiently close packing under pressure. PNGE-D-MCH/52A 12 49. Consider 1௩௦ Which of the above conditions are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (0 1, 2 ஊக 3 following statements regarding mechanical properties of metals : 1. The phenomenon leading to fracture under repeated stresses having a maximum value less than the ultimate strength of material is called creep. 2. A _ time-temperature parameter used to predict stress rupture due to creep is called Larson-Miller parameter. 3. Time-dependent deformation of a material when subjected to a constant load or stress is called fatigue. Which of the above statements is/are correct? (a) 1 and 2 only (b) 2 only (c) 3 only (2) 1, 2 and3 50. Consider 115 following statements regarding mechanical properties of metals : 1. The process of atoms moving over each other during the permanent deformation of a metal is called slip. 2. An empirical equation that relates the strength of a metal to its grain size is known ലട Hall-Petch relationship. 3. The ability of some metals to deform plastically by 1000-2000 percent at high temperatures and low loading rates is called super- plasticity. Which of the above statements are correct? 53. The 52. A high-performance four-stroke SI engine has a compression ratio 10:1. The ideal air standard Otto cycle efficiency is 0-602. The indicated efficiency is 55 percent of the corresponding ideal air standard Otto cycle efficiency. The engine mechanical efficiency 15 85 percent, and the volumetric efficiency is 90 percent. The calorific value of the fuel is 44 MJ/kg. What is the engine arbitrary overall efficiency? (a) 90 (0) 28:1% (© 9 (व) 305% performance test of धा) air- conditioning unit rated as 1407 kW (40 TR) seems to be indicating poor cooling. The test on heat rejection to atmosphere in its condenser shows the following : Cooling water flow rate : 4 L/s Water temperatures : In 30 °C; Out 40 °C Power input to motor : 48 kW (95% efficiency) (a) 1 and 2 only (b) 2 and 3 only What is the actual refrigeration capacity of the unit? (The specific heat capacity of water 15 4:1868 kJ/kg-K) (a) 1015 kW (૭) 167-4 kW (જ 121:9kW (ठ) 189. kW (c) 1 and 3 only (0) 1, 2 and3 51. The Rolls-Royce (৮12 turbocharged four-stroke direct injection diesel engine has a displacement of 26:1 litres. The engine has a maximum output of 900 kW at 2300r.p.m. What is the brake mean effective pressure? 54. If the partial pressure of water vapour for the mixture of dry air and water vapour is 12:79 mm Hg and its total pressure is 736 mm Hg, then what is the specific humidity? (a) 18 bar চি) 15 bar (a) 0:068 kg w.v./kg 0.৪. (0) 0011 kg w.v./kg 6.೩. (೦ 10:15 bar (૦ 0-023 kg w.v./kg 6.೩. (व) 21 bar (व) 0044 kg w.v./kg d.a. PNGE-D-MCH/52A 13 ۲۶۵ 55. If 1m? of a gas is compressed adiabatically (the ratio of specific heats = 14) from 1 bar to 5 bar in a reciprocating compressor, what is the work of compression? (a) 192543 N-m (b) 245361 N-m (c) 158643 N-m (d) 204050 N-m 56. An R134a thermostatic expansion valve, not equipped with an external equalizer, has a superheat setting of 7 °C, while supplying the refrigerant to the evaporator at 0 °C. The power fluid is same as refrigerant. What 15 the difference in pressure in opposite sides of the diaphragm required to open the valve? (Consider evaporator pressure at 0°C and 7°C as 2928 bar and 3748 bar respectively) (a) 2928 bar (0) 3748 bar (c) 0-82 bar (d) 6676 bar 57. A machine working on a Carnot cycle operates between 305K and 260K. What is the COP when it is operated as a refrigerating machine? (2) 5-78 (b) 5 (0) 1:17 (৫) 6.78 PNGE-D-MCH/52A 14 58. A cold storage plant is required to store fish. The fish is supplied at a temperature of 30 °C. The fish is stored in cold storage which is maintained at -8 °C. If the plant requires 75 kW to drive it, what is the capacity of the plant? (Assume actual COP of the plant as 0:3 of the Carnot COP) (a) 40-8 TR (b) 359 TR (© 448 TR (0 546 TR 59. On a particular day, the atmospheric air records a partial pressure of water vapour 9:62 mm Hg and the saturation pressure of vapour is 31-8 mm Hg. The barometric pressure is observed to be 756mm Hg. What are the relative humidity and the specific humidity respectively? (a) 30-25%, 0-008 (b) 30-25%, 0-014 (c) 35-87%, 0-014 (૭) 35-87%, 0-008 60. A small water-cooled condenser uses mains water at 13 °C and heats this to 24°C before it goes to waste. The evaporator duty is 4-2 kW and the motor output is 1:7kW. What is the water mass flow? (a) 0:09 kg/s (b) 0:19 kg/s (c) 0-21 kg/s (0 0:13 kg/s 61. Air circulates at the rate of 68 kg/s and is to be heated from 16°C to 34°C. What is the water mass flow for an air heater coil having hot water entering at 85°C and leaving at 74°C? (Take specific heat of air at constant pressure as 1:02 kJ/kg-K and specific heat of water as 4:187 kJ/kg-K) (a) 19 kg/s (b) 17 kg/s (c) 27 kg/s (d) 14 108/5 62. A six-cylinder four-stroke diesel engine develops 125kW at 3000r.p.m. 118 brake-specific consumption 18 200 gm/kWh. What is the quantity of fuel to be injected per cycle per cylinder? (The specific gravity of the fuel is 0:85) (a) 0۰0726 cc/cycle (0) 0:0379 cc/cycle (જ 00981 cc/cycle (0) 00545 cc/cycle PNGE-D-MCH/52A 15 63. In acrank and slotted lever quick return motion mechanism, the _ distance between the fixed centres is 240 mm and the length of the driving crank is 120mm. What is the time ratio of cutting stroke to return stroke? (a) 1 (b) 05 धि ટ્રે 3 رم 64. ABCD is a four-bar chain in which link AD is the driver, link BC is the driven, and DC is fixed. The driver rotates uniformly at a speed of 120r.p.m. and the constant driving torque is 50 N-m. At a particular phase of the mechanism, the angular velocity of the driven link is 2 rad/s. What is the ideal mechanical advantage? (a) 6 (b) 6:28 (9 8:98 (व) 10 (2.1.0. 65. The distance between two parallel shafts is 18 mm and they are connected by an Oldham’s coupling. The driving shaft revolves at 160r.p.m. What 15 the 67. The number of teeth of a spur gear is 30 and it rotates at 200 r.p.m. What is the pitch line velocity if it has a module of 2 mm? maximum speed of sliding of the tongue of the intermediate piece along its groove? (a) 3769 mm/s (b) 628:3 mm/s (a) 0415 m/s (© 8507 mm/s (व) 2461 mm/s (b) 0*586 m/s 68. Two spur gears have a velocity ratio of 1/3. If the driven gear has 72 teeth, then what is the number of teeth of the driver gear? (જ 0:302 m/s (व) 0845 m/s (2) 72 (b) 36 (c) 24 66. In a thrust bearing, the external and the internal diameters of the contacting (0) 12 surfaces are 320mm and 200mm respectively. The total axial load is 80 kN. The shaft rotates at 400 r.p.m. Taking the coefficient of friction as 0:06, what is the power lost in overcoming the friction? 69. The following data relate to two meshing gears : Velocity ratio = 1/3 Module = 4mm Centre distance = 200 mm (a) 26-602 kW- How many number of teeth are there on the gear wheels? (b) 21kW (a) 90 60 (c) 44:23 kw ۳ () 45 (0) 7 (0) 75 PNGE-D-MCH/52A 16 70. An epicyclic gear train consists of an arm and two gears A and B having 30 teeth and 40 teeth respectively. The arm rotates about the centre of gear A ata speed of 80 7.0.1. counterclockwise. What is the speed of gear B if gear A is fixed? (a) 140 r.p.m. (b) 180 r.p.m. (c) 120 r.p.m. (৭) 200 r.p.m. 71. A flywheel with a mass of 3kN has a radius of gyration of 1-6 11, What is the energy stored in the flywheel when its speed increases from 315 r.p.m. to 340 r.p.m.? (a) 7575 kJ (0) 8962 kJ (૭ 4192: kJ ‎kJ‏ 6849 رم ‎72. A flywheel fitted to a steam engine has a ‎mass of 800 kg. Its radius of gyration is 360mm. The starting torque of the engine is 580 N-m and may be assumed constant. What is the kinetic energy of the flywheel after 12 seconds? ‎(a) 233-27 kJ (b) 263-27 kJ (c) 333-27 kJ ‎(૭) 363:27 kJ ‎PNGE-D-MCH/52A ‎17 ‎73. An aeroplane makes a complete half ‎circle of 50 metres radius, towards left, when flying at 200 km/h. The rotary engine and propeller of the plane have a mass of 400 kg and radius of gyration of 0:3 m. The engine rotates at 2400 r.p.m. clockwise when viewed from the rear. What is the gyroscopic couple on the aircraft? ‎(a) 10 kN-m (b) 15 kN-m (જ 18 kN-m ‎(a) 12 kN-m ‎74. What is the vertical height of a Watt ‎governor when it rotates at 60 r.p.m.? (a) 0۰157 m (0) 0192 m (© 0205 m ‎(d) 0:248 m ‎75. The degree of freedom (DOF) for globular ‎or spherical pair is (a) 1 ‎(b) 2 ‎જિ -1 ‎(9 3 ‎1.7.೦. 76. A turbine develops 9000kW when running at a speed of 150r.p.m. and under a head of 30m. What is the specific speed of the turbine? (a) (৮) اص (6) 77. Consider 202 r.p.m. 152 r.p.m. 189 r.p.m. 217 r.p.m. the following statements regarding unit quantities : ۶ Unit specific speed is defined as the speed of a turbine working under unit head. Unit discharge is defined as the discharge passing through a turbine, which is working under a unit head. Unit power is defined as the power developed by a turbine working under unit speed. Which of the above statements is/are correct? (a) धि (6) (0) 1 and 3 2 and 3 2 only 3 only PNGE-D-MCH/52A 18 78. Consider the following statements regarding characteristic curves of hydraulic turbines : 1. Main characteristic curves are obtained by maintaining a constant speed and a constant gate opening on a turbine. 2. Operating characteristic curves are obtained by maintaining a constant head on a turbine. 3. Constant efficiency curves are known as Muschel curves. Which of the above statements is/are correct? (a) 1 and 2 (b) 2 and 3 (c) 2 only (৭) 3 only 79. Consider the following statements regarding centrifugal pumps : 1: The rotating part of a centrifugal pump is called runner. Volute casing is spiral type in which area of flow increases gradually. In vortex casing, a vortex chamber is introducing between the casing and impeller. Foot valve is fitted at the lower end of suction pipe. Which of the above statements are correct? (a) 1, 2 and 3 only (b) 2, 3 and 4 only (6) 1, 3 and 4 only (0) 1, 2, 3 and 4 80. Consider the following statements : 1. The horizontal distance between the centreline of the pump and the water surface in the tank to which water is delivered is known as delivery head. 2. The sum of suction head and delivery head is known as static head. 3. The manometric head is defined as the head against which a centrifugal pump has to work. Which of the above statements is/are correct? (a) 1 and 3 (b) 2 and 3 (c) 1 only (0) 2 only 81. Consider the following statements regarding efficiencies of a centrifugal pump: 1. The ratio of the manometric head to the head imparted by the impeller to the water is known as manometric efficiency. PNGE-D-MCH/52A 19 2. The ratio of the power available at the impeller to the power at the shaft of the centrifugal pump: is known as overall efficiency. 3. The ratio of the power output of the pump to the power input to the pump is known as mechanical efficiency. Which of the above statements is/are correct? (a) 1 and 3 (b) 2 and 3 (c) 1 only (97 3 only 82. The outlet velocity of flow and outlet velocity of whirl of an impeller of a centrifugal pump are 5 m/s and 12 m/s respectively. What is the resultant velocity at outlet? (a) 17 m/s ಗಿ) 7 m/s (જી 11 m/s (0) 13 m/s (೫.7.೦. 83. Consider 1006 84. Consider 1006 following statements regarding steam nozzles : 1. Nozzle efficiency is defined as the ratio of the actual enthalpy drop to the isentropic enthalpy drop between the same pressures. 2. Velocity coefficient is defined as the ratio of the actual exit velocity to the exit velocity when the flow is isentropic between the same pressures. 3. Velocity coefficient is the square root of nozzle efficiency. Which of the above statements are correct? (a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (૭) 1, 2 and 3 following statements regarding steam turbines : 1. Blade efficiency is the ratio of the work done on the blade per second to the energy entering the blade per second. 2. Internal efficiency is the ratio of the heat converted into useful work to the total adiabatic heat drop. 3. Net efficiency is the ratio of brake thermal efficiency to diagram thermal efficiency. PNGE-D-MCH/52A 20 Which of the above statements are correct? (a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (व) 1, 2 and 3 85. Consider the following statements : 1. Bleeding is the process of draining steam from the turbine at certain point during its expansion. 2. There is a usual practice in bleeding installation to allow the bled steam to mix with the preheated air, after that the mixture of steam and air proceeds to the boiler. 3. The objective of governing is to keep the turbine speed fairly constant irrespective of load. Which of the above statements are correct? (a) 1 and 3 only (b) 2 and 3 only (c) 1 and 2 only (0) 1, 2 and 3 86. The indicated work of a single-stage reciprocating air compressor 18 250 kJ/min. What is the indicated power? (a) 250 kw (b) 0-24 kw (© 15 kw (0 416 kw 87. Consider the following statements : 1. Thermal efficiency is the ratio of the network output to the heat supplied. 2. Compressor isentropic efficiency is the ratio of the work output in isentropic compression to the ideal work required. 3. Turbine isentropic efficiency is the ratio of the actual work output to the isentropic work output. Which of the above statements are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (0 1,2 and 3 88. Consider the following statements regarding modes of failure : 1. A ductile material is one which has a relatively large tensile strain before fracture takes place. 2. AQ brittle material has a relatively small tensile strain before fracture. 3. A static load is defined as a force, which is gradually applied to a mechanical component and which changes its magnitude or direction with respect to time. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only ( 2 and 3 only (व) 1, 2 and 3 PNGE-D-MCH/52A 21 89. Consider the following statements regarding theories of elastic failure : 1 Experimental investigations suggest that maximum principal stress theory gives good predictions for brittle materials. Maximum shear 50055 theory predicts that the yield strength in shear is equal to the yield strength in tension. Maximum shear stress theory is also known as Coulomb, Tresca and Guest theory. Which of the above statements are correct? (a) (b) (c) 1 and 2 only 1 and 3 only 2 and 3 only (0) 1, 2 and 3 90. Consider the following statements regarding distortion energy theory : 1, It is known as Huber-von Mises- Hencky theory. The yield strength in shear is 7 times the yield strength in tension. Experiments have shown that the distortion energy theory is in better agreement for predicting the failure of a brittle component than any other theory of failure. Which of the above statements are correct? (a) (b) (c) (व) 1 and 2 only 1 and 3 only 2 and 3 only 1, 2 and 3 (೫.7.೦. 91. Consider the following statements regarding low-cycle and_high-cycle fatigue : 1. Any fatigue failure, when the number of stress cycles is less than 1000, is called low-cycle fatigue. 2. Any fatigue failure, when the number of stress cycles is more than 1000, is called high-cycle fatigue. 3. The high-cycle fatigue involves plastic yielding at localized areas of the components. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 and 3 92. Consider the following statements regarding joints : 1. Bolted joint is the example of permanent joint. 2. Cotter joint is the example of separable joint. ૩. In hand riveting, a die is placed on the protruding end of the shank and blows are applied by a hammer. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 and 3 PNGE-D-MCH/52A 22 93. Consider the following statements regarding transmission shaft : 2: Countershaft is a secondary shaft, which is driven by the main shaft and from which the power is supplied to a machine component. Spindle consists of a number of shafts, which are connected in axial direction by means of couplings. Jackshaft is an auxiliary shaft between two shafts that are used in transmission of power. Which of the above statements are correct? (a) (b) (0) (0) 1 and 2 only 1 and 3 only 2 and 3 only 1, 2 and 3 94. A pair of spur gears consists of a 20 teeth pinion meshing with a 120 teeth gear. The module 15 4 mm. What is the centre distance? (a) (৮) (© (6) 210 mm 280 mm 310 mm 325 mm 95. In a particular application, the expected 97. life for 90% of the bearings is 8000 1. What is the rated bearing life when the shaft rotates at 1450 r.p.m.? (0) 607 million revolutions (b) 641 million revolutions (c) 696 million revolutions (व) 712 million revolutions Consider the following statements regarding lubricant : و Molybdenum disulphide is semi- solid lubricant. It is used to protect bearing from corrosion. It is used to reduce wear. Which of the above statements are correct? 96. Consider the following statements : (a) 1 and 2 only 1. Zero film bearing is a bearing which operates without any lubricant. (b) 1 and 3 only 2. Thin film lubrication describes a condition of lubrication, where two (c) 2 and 3 only surfaces of the bearing in relative motion are completely separated by (a) 1, 2 and 3 a film of fluid. 3. Hydrodynamic lubrication is defined as a system of lubrication 98. A solid cast iron disc, 1130-97 kg mass, in which the load-supporting fluid film is created by the shape and relative motion of 1006 sliding surfaces. ५ Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 PNGE-D-MCH/52A 23 is used as a flywheel. The radius of gyration of the solid disc 15 0:3535 m about its axis of rotation. It is rotating at an angular speed of 36-65 rad/s and brought to rest by means of a brake. The energy absorbed by the brake is (a) (b) (6) (0) 61 kJ 76 kJ 94 kJ 107 kJ (೫.7.0. Consider the following statements regarding functions of flywheel : 1. It stores and releases energy when needed during the work cycle. 2. It increases the power capacity of the electric motor or engine. 3. It reduces the amplitude of speed fluctuations. Which of the above statements are correct? (a) (৮) (c) 2 and 3 only 1 and 2 only 1 and 3 only (0) 1, 2 and3 100. Consider the following statements : 1. The governor controls the mean speed of the engine by varying the fuel supply to the engine. 2. The flywheel has no influence on the mean speed of the engine. 3. A flywheel may be used if the cyclic fluctuations of energy output are negligible. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 PNGE-D-MCH/52A 101 102 24 * The yearly duration curve of a certain power plant can be considered as a straight line from 350 MW to 80 MW. Power is supplied with one generating unit of 250 MW capacity and two units of 150 MW capacity each. What is the utilization factor? (a) 6 (0) 0-536 (5) 0-636 (0 0-736 „ Which one of the following is Dulong’s formula for the calculation of the calorific value of the solid or liquid fuels from their chemical composition? (Where H, O and S are hydrogen, oxygen and sulphur in percentage respectively in 100 kg of fuel) (a) 1೦೪ ട-1-[13800- 1440008 ue 100 ৪ +72709] kJ/kg (૭) ೫೦೪ = -1 [23800 + 144000/11 டு 100 8 + 8270S] kJ/kg © ೫೦೪ = _1 [838004 1440001 ୦ 100 8 4 92708] kJ/kg (d) None of the above 103. Consider the following statements regarding steam turbines : 1. In reaction turbine, the steam expands in the stationary nozzles and attains high velocity. 2. In impulse turbine, the steam enters the fast moving blades on the rotor from stationary nozzles; if the steam is superheated before allowing it to expand, the Rankine cycle efficiency may be increased. 3. In impulse turbine, the resulting high velocity steam impinges against the blades which alter the direction of steam jet thus changing the momentum of jet and causing impulsive force on the blades. 4. In steam turbine, the steam consumption does not increase with increase in years of service. Which of the above statements are correct? (a) 1 and 2 മു 2 and 3 (જ 3 and 4 (0) 1 and 4 PNGE-D-MCH/52A 25 104. The overall thermal efficiency of a 40 MW turbo alternator is 30%. If the load factor of the power station is 50% and the coal burnt has a calorific value of 6800 kcal, what is the energy produced per day? (a) 44 × 105 kWh (b) ` 48 × 105 kWh (0 34 × 105 kWh (0 38 × 104 kWh 105. Consider the following statements regarding steam power plants : 1. An increase in the initial pressure of steam raises the thermal efficiency. The thermal efficiency will be dropped by raising the initial temperature of the steam without changing the pressure. Intermediate reheating of steam improves the thermal efficiency of the plant. An increase in the initial pressure of steam improves the thermal efficiency of steam power plant and also wetness fraction of such steam decreases at the end of expansion. Which of the above statements are correct? (a) 1 and 2 മു 2 and 3 () 3 and 4 (0 1 809 3 (2.1.౦. 106. Consider the following statements regarding cooling towers in thermal power plants : 1. Ina natural draught cooling tower, the cold water is allowed to fall over louvers. 2. In an atmospheric type cooling tower, the hot water from the condenser is pumped 10 the troughs and nozzles situated near the bottom. 3. In forced draught cooling towers, draught fans are installed at the bottom of towers. 4. Mechanical draught cooling towers may be forced draught cooling towers or induced draught cooling towers. Which of the above statements are correct? (a) 1 and 2 (b) 2 and 3 (c) 3 and 4 (৫) 1 and 3 107. Consider the following statements regarding steam condensers : 1. Power plant cycle improves in efficiency as the turbine exhaust pressure drops’ with steam condenser. PNGE-D-MCH/52A The use of condenser decreases the size of boiler installation. The vacuum obtainable in a condenser is governed by the inlet water temperature which in turn varies with the amount of condensing water used per kg of steam and its initial temperature. Which of the above statements are correct? (0) (৮) (6) (0) 1 and 2 only 2 and 3 only 1 and 3 only 1, 2 and 3 108. Multi-cylinder turbines which have their rotors mounted on one and the same shaft and coupled to a single generator are known as (a) (৮) (c) (0) single-shaft turbines multi-axial turbines topping turbines back pressure turbines 109. Consider the following features for a gas turbine plant : 1. Intercooling 2. Regeneration 3. Reheat Which of the above features in a gas turbine cycle increase the _ specific output and thermal efficiency of the plant? (a) 1, 2 and 3 (b) 1 and 2 only (c) 2 and 3 only (d) 1 ৪003 only Consider the following statements regarding combustion of fuels : 1. Carbon combines with oxygen to form carbon monoxide. 2. Hydrogen burns with oxygen to give water as the product. 3. When methane burns in 1006 presence of oxygen, the combustion products are carbon dioxide and water vapours. Which of the above statements are correct? (a) 1 and 3 only (b) 1 and 2 only (c) 2 and 3 only (0) 1, 2 and 3 PNGE-D-MCH/52A 27 112. Consider 1006 111. Consider the following statements : 1. Air contains 23% of oxygen and 77% of nitrogen by volume. 2. The main constituents of natural gas are methane and ethane. 3. Coal gas mainly consists of hydrogen, carbon monoxide and hydrocarbons. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0) 1, 2 and 3 following statements regarding properties of good coal : 1. It should have low ash content and high calorific value. 2. It should have large percentage of sulphur (more than 25%). 3. It should have high grindability index. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 [ P.T.O. 113. Which one of the following interpersonal Which of the above statements is/are roles the manager is expected to train, correct? counsel, mentor and encourage for high employee performance? (a) 2 only (a) Figurehead role (b) 1 and 3 only (b) Leader role (c) 2 and 3 only (c) Liaison role (2) 1, 2 and 3 (व्‌) Monitor role 116. Consider the following statements regarding computer-aided manufac- 114. Which one of the following approaches turing : includes application of _ statistics, optimization models, information ৰ ti 1. Inventory control is concerned with models and computer simulations? managing and controlling the (a) Quantitative approach physical operations in the factory. 2. Manufacturing control is concerned with the demand fulfilment and also to reduce the inventory to eliminate the wastage and extra money investment. (b) Qualitative approach (c) Contingency approach (৫) Behavioural approach 3. Shop floor control is concerned with the problem of monitoring the progress of processing, assembling, and inspection of the products in the factory. 115. Consider the following statements regarding purpose of the micromotion study : 1. 1£ 18 to study the nature and path of movements for accomplishing the Which of the above statements is/are elements of an operation. correct? 2. It is to impart training to the operators regarding motion economy 9౧౦1168 ૭૦ that unnecessary motion or movement by the operators may be avoided. (a) 1 and 2 only (b) 1 and 3 only (c) 3 only 3. 1018 to find the most efficient way of accomplishing the elements. (व) 1, 2 and 3 PNGE-D-MCH/52A 28 117. Which of the following is/are not 119. Consider the following statements included in flexible manufacturing regarding costs associated with a system workstation facilities? project : 1. Direct costs increase with time. 6૭) Machining’centres 2. Direct costs are normal costs that can be assigned directly to a (b) Milling modules specific work package or project activity. 3. Crashing activities increase direct (c) Inspection stations costs. (d) Welding workspace Which of the above statements are correct? (a) 1 and 2 only 118. Consider the following statements (b) 1 and 3 only regarding pure project : ए (જ 2 and 3 only 1. The project manager has full (0 1, 2 and 3 authority over the project. : 120. Consider the following statements 2. Team members report to one boss. ଓ regarding redundancy : 3. It has longest communication 1. Warm redundancy is also known as chains. hot redundancy. 2. Active redundancy is also known as Which of the above statements are ல்‌ न correct? 3. Passive redundancy is also known as standby redundancy. (a) 1 and 2 only Which of the above statements is/are correct? (b) 1 and 3 only (a) 1 only (b) 3 only (c) 2 and 3 only (c) 2 and 3 only ‎೫63 (୩ 1, 2 छत 3‏ 2 ,1 رم ‎PNGE-D-MCH/52A 29 [મા છ. 121. In which one of the following casting 123. Which one of the following instruments processes, thin slabs are produced from is commonly used for measuring the molten metal? thickness and inside or outside dimensions of parts? (a) Gravity die casting (a) Micrometer (b) Centrifugal casting (b) Anvil (c) Plaster casting (c) Sine bar (व) Strip casting (0) Surface plate 122. Consider the following statements regarding forging : 124. The technique that creates ৪ three- 1. In incremental forging process, a dimensional image of the part by tool forges a blank into a shape in utilizing an optical system is called several small steps. (a) thermal inspection 2. In isothermal forging process, the process heats the dies to the same temperature as that of the hot ‏ا‎ ‎workpiece. eddy current inspection (c) holography 3. In rotary swaging process, a solid rod is subjected to radial impact forces by a set of reciprocating dies of the machine. (व) radiography ਜਸ 1 സഭ ಹ ક દાદ রর 125. The welding flame with excess oxygen is correct? known as (a) 1 and 2 only (a) oxidizing flame (b) 1 and 3 only (b) carburizing flame (c) 2 and 3 only (c) reducing flame (व) 1, 2 ৪003 (0) neutral flame PNGE-D-MCH/52A 30 126. Consider the following statements regarding solar energy : 1. The sun radiates energy uniformly in all directions in the form of electromagnetic waves. 2. The output of the sun 18 2. 8 × 1023 kw. 3. The energy reaching the earth is 1-1x 1012 kWh/year. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0) 1, 2 ೫43 127. Consider the following statements regarding measurement 0? solar radiation : 1. Pyranometer cannot measure diffuse radiation. 2, Pyrheliometer is an instrument that measures beam radiation. 3. A sunshine recorder measures the sunshine hours in a day. PNGE-D-MCH/52A Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0) 1, 2 and 3 128. Consider the following statements : 1. The sum of beam and diffuse radiation is referred to as global radiation. 2. Diffuse radiation does not have a unique direction. 3. Solar radiation propagating in a straight line and received at the earth surface without change of direction is called direct radiation. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 ೫63 (2.7.0. 129. Consider the following statements regarding depletion of solar radiation : 1. Nitrogen gas absorbs the X-rays and extreme ultraviolet radiations. 2. Dust particles and air molecules absorb a part of solar radiant energy irrespective of wavelength. 3. Ozone cannot absorb ultraviolet radiation. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0) 1, 2 and 3 130. Consider the following statements : 1. Solar radiation incident on the outer atmosphere of the earth is known as extra radiation. 2. Solar radiation that reaches the earth surface after passing through the earth’s atmosphere is known as terrestrial radiation. 3. The term ‘solar insolation’ is defined as solar radiation energy received on a given surface area in a given time. PNGE-D-MCH/52A Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 131. Consider the following statements regarding solar collectors : 2 Collector efficiency is defined as the ratio of the energy actually absorbed and transferred to heat- transporting fluid by the collector to the energy incident on the collector. Concentration ratio is defined as the ratio of the area of the receiver to the area of aperture of the system. Temperature range is the range of temperature to which the heat- transporting fluid is heated up by the collector. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 ೫63 132. Consider the following statements : 1. The concentration ratio achieved from compound parabolic concen- trator collector is in the range of 3-7. 2. The concentration ratio in the range of 70-80 may be achieved from cylindrical parabolic concen- trator collector. 3. Aconcentration ratio of 10-30 may be achieved from linear Fresnel lens collector which yields tempera- tures between 150 °C and 300 °C. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 and 3 Consider the following statements regarding solar greenhouse : 1. If natural means are adopted to collect, store and distribute the energy inside, it is known as active greenhouse. 2. In cold countries, ‘winter green- houses’ provide supplementary heat + maintain adequate temperature during cold months when solar insolation is low. 3. Greenhouses for arid zone are designed to conserve’ water resources. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 PNGE-D-MCH/52A 33 Consider the following statements regarding wind energy : 1. The rate of change of wind speed with height is called wind shear. 2. The layer of air from ground to gradient height is known .as planetary boundary layer. 3. 1౧ the surface layer, the mean wind speed with height can _ be represented by Prandtl logarithmic law model. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0) 1, 2 and 3 Consider the following statements regarding biomass energy : 1. Charcoal is obtained by biomiza- tion process of woody biomass to achieve higher energy enthalpy per unit mass, 2. Biodiesel is simple 1௦ use, biodegradable and non-toxic. 3. The raw vegetable oil is upgraded as biodiesel through a chemical process called trans-esterification. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 (೫.7.೦. 136. Consider 115 137. Consider 115 following regarding tidal energy : statements 1. When the sun-earth and moon- earth directions are perpendicular, the solar and lunar tides are out of phase producing net tides of maximum range. 2. Neap tides occur twice per month at times of half-moon. 3. Spring tides occur twice per lunar month at times of both full and new moon. Which of the above statements are correct? 1 (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and3 following statements regarding phosphoric acid fuel cell : 1. The basic phosphoric acid fuel cell consists of two electrodes of porous conducting material 10 collect charge. 2. At the negative electrode, hydrogen gas is converted to hydrogen ions. 3. Pure hydrogen or a hydrogen-rich gas is supplied at positive electrode and oxygen or air is supplied at negative electrode. PNGE-D-MCH/52A 34 138. Consider the Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 following statements regarding visual perception : 1. Vision is the most important sensory channel for humans. 2. The function of visual perception is to provide visual input to support a robot’s learning process. 3. Vision plays a vital role in any machine which intends to perform autonomous motions. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (व) 1, 2 and 3 139. Trajectory is a path (a) without time constraint (b) with time constraint (c) in one-dimensional space (0) with a motion planning strategy 140. Collision-free path of the trajectory requires (a) constrained motion of the work- space (b) time constraint (c) geometric model of the workspace (d) kineto-dynamic chain 142. Consider 006 143. Consider 1006 141. The purpose of defuzzification is to make a decision based on (a) fuzzy output set (b) fuzzy input set (c) Boolean set (0) motion set following statements regarding issues in robotics : 1. ^ 709005 degree of autonomy depends on its ability to perform the ordered sequence of perception, decision-making and action. 2. Kinematics is the study of motion in relation to force and torque. 3. Dynamics is the study of motion without consideration of force and torque. Which of the above statements is/are correct? (a) 1 only (b) 1 and 2 only (c) 2 and 3 only (व) 1, 2 and 3 following statements regarding joints : 1. A joint is the connection between two or more links at their nodes. 2. If a joint connects only two links, the entity is also called a kinematic pair. 3. If a one degree of freedom joint imposes a translational motion, it is called a prismatic joint. PNGE-D-MCH/52A 35 Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (2) 1, 2 and 3 HARO-1 is (a) a prototype of robotic animal (b) a prototype of human-like robot (c) a prototype of robotic engine (d) a prototype of robotic bird Consider the following statements regarding sensing elements : 1. A human sensory system can be divided into five distinct sub- systems. 2. MEMS stands for ‘Micro-Electro- Mechanical System’. 3. The walking procedure involves unpredictable movement done by a robot. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and3 (2.7.0. 146. The physical quantities related to touch are measured by (a) (b) (0) (a) 147. Consider simple sensors reflective sensors tactile sensors touch sensors the following statements regarding joint-space control : 7 The motion performed by a robot is the input motion of its mechanism. The control scheme at the lowest level of a robot’s motion control system is called joint-space control. A robot is a machine which is skilled at executing motions. Which of the above statements are correct? (a) (৮) ‏اص‎ ‎(0) 148. Autonomy 1 and 2 only 1 and 3 only 2 and 3 only 1, 2 and 3 is a characteristic which describes (a) (b) (6 (0) an automated system’s degree of independence an automated system’s degree of freedom an automated behaviour an automated action PNGE-D-MCH/52A 149. Consider the following statements regarding monocular vision : 1. The monocular vision system takes images as input, and produces geometrical measurement as output. 2. A monocular vision system 15 normally composed of ৪ single electronic camera, an image digitizer and computing hardware. 3. The electrical signals, picked up by the imaging sensor of the camera, will be converted into an analogue image. Which of the above statements are correct? (a) 1 and 2 only (b) 1 and 3 only (c) 2 and 3 only (0 1, 2 and 3 150. The function of parallel splitter motion is to (a) duplicate the input motion into 36 (b) (6 (0) multiple output motions duplicate the split input motion into multiple parallel input motions duplicate the split input motion into multiple random input motions duplicate the multiple random input motions into single input motion SPACE FOR ROUGH WORK PNGE-D-MCH/52A 37 [ P.T.O. SPACE FOR ROUGH WORK PNGE-D-MCH/52A 38 SPACE FOR ROUGH WORK PNGE-D-MCH/52A 39 1೫.7.೦. SPACE FOR ROUGH WORK kkk PNGE-D-MCH/52A 40 SB24—16740