| 4th March 2016 10:30 AM | |
| Shaleen | Re: Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers As you have asked about the ONGC previous year paper questions, check below for the information 1 What is the difference between isotropic and anisotropic materials? Ans If a material exhibits same mechanical properties regardless of loading direction, it is isotropic eg., homogeneous cast materials. Materials lacking this property are anisotropic 2 what are orthotropic materials It is a special class of anisotropic materials which can be described by giving their properties in three perpendicular direction et wood composites 3 A plain carbon steel has BHN of 180 What are values of Rc, VHN and ultimate strength? Ans Rc-RHN/10 18,VHN BHN 180 4 What properties need to be considered for applications calling for following requirement: irigdity strength for no plastic deformation under static load wear resistance reliability and safety Ans Rigidity- elastic modules and yield strength Strength for no plastic deformation under static loading-yield point Wear resistance-Hardness Reliability and safety-Endurance limit and yield point 5 Explain the effects of alloying chromium and nickel in stainless steel. Addition of nickel and chromium increases the tensile strength and increase in resistance to corrosion takes place. 6 Mention two types of dislocation, Dislocation refers to a break in the continuity of the lattice. In edge dislocation, one place of atoms gets squeezed out.In screw dislocation the lattice atoms move from their regular ideal positions. 7 What are the principal constituents of brass? Principal constituents of brass are copper and zinc 8 what is curie point? Curie point is te temperature at which ferromagnetic materials can no longer be magnetized by outside forces 9 Specific strength of materials is very high when they are in fiber size but lower when they are in bar form-Why? Crystal structure has ordered, repeating arrangement of atoms, fibers are liable to maintain this and thus have high specific strength. As size increases, the condition of ordered and repeating arrangements cant be guaranteed because of several types of defects and dislocations and thus the specific strength gets lower 10 what is the percentage of carbon in cast iron? 2.5% 11 Which element is added in steel to increase resistance to corrosion? Chromium 12 whether individual component material retain their characteristics or not Yes 13 An elastomer is a polymer when its percentage elongation rate is Greater than 100% 14 If % elongation of material is more tha 200% it is classed as Rubber 15 Why is it that the maximum value which the residual stress can reach is the elastic limit of the material? A stress in excess of elastic limit with no external force to oppose it will relieve itself by plastic deformation until it reaches the value of the yield stress 16 Why fatigue strength decreases as size of a part increase beyond around 10 mm? Perfection of material conditions is possible at lower sizes and as size increases, it is not possible to attain uniform structure of the material 17 Distinguish between creep and fatigues Creep is low and progressive deformation of a material with time under a constant stress at high temperature application. Fatigue is the reduced tendency of material to offer resistance to applied stress under repeated or fluctuating loading conditions? 18 While normal carbursing and nitriding surface treatments increase fatigue strength excessive treatment may decrease the fatigue strength Why Normal carbursing/nitiriding treatments increase volume due to phase transformation at surface and introduce residual compressive surface stress and thus increase the fatigue strength, By excessive treatment the high compressive stresses are introduced but these are balanced by high internal tensile stresses of equal value and the subsurface fatigue cracks may develop in the regions of high tensile stress and lead to early fatigue failures 19 List at least two factors that promote transition form ductile to brittle fracture Manner of loading and the rate of loading promote transition from ductile to brittle fracture, A machine member may have ductile failure under static loading but may fail in brittle fashion when the load is fluctuating Similarly a material may evidence ductile failure under tensile loading at ordinary testing speed but if load is applied at a high velocity then failure may be brittle 20 Which theories of failure are used for (a) ductile material and (b) brittle materials For ductile materials theories of failure used are maximum shear stress theory, and maximum energy of distortion theory, while for brittle materials theory of maximum principal stress and maximum strain are used 21 what is stellite? I t is a non ferrous cast alloy containing cobalt chromium and tungsten 22 Car tyres are usually made of styrene butadine rubbe 23 What is the structure of pure iron and whether it is soft or hard? Ferrite and it is soft 24 which elements increase the corrosion resistance of steel? Chromium and nickel 25 Which rays are produced by cobalt 60 in industrial radiography? Gamma rays |
| 4th March 2016 10:28 AM | |
| Unregistered | Re: Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers Hello sir, I am Kamal Kishore. I am from Jaipur. I want you to help me by providing me with the Oil and Natural Gas Corporation Limited Mechanical Engineering last year paper questions? |
| 25th July 2014 10:35 AM | |
| Arun Vats | Re: Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers As you want to get the Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers so here it is for you: 1 During the execution of a CNC part program block NO20 GO2 X45.0 Y25.0 R5.0 the type of tool motion will be A) circular Interpolation — clockwise B) circular Interpolation — counterclockwise C) linear Interpolation D) rapid feed Answer : (A) 2 A component can be produced by any of the four processes I, II, III and IV. Process I has a fixed cost ofRs. 20 and variable cost of Rs. 3 per piece. Process II has a fixed cost Rs. 50 and variable cost of Re. 1 per piece. Process III has a fixed cost of Rs. 40 and variable cost of Rs. 2 per piece. Process IV has a fixed cost of Rs. 10 and variable cost of Rs. 4 per piece. If the company wishes to produce 100 pieces of the component, from economic point of view it should choose A) Process I B) Process II C) Process III D) Process IV Answer : (B) 3 In an interchangeable assembly, shafts of size 25.000+0.040mm mate with holes of size 25.000+0.020 mm. The maximum possible clearance in the assembly will be A) 10 microns B) 20 microns C) 30 microns D) 60 microns Answer : (D) 4 A company has two factories S1, S2 and two warehouses D1, D2. The supplies from S1 and S2 are 50 and 40 units respectively. Warehouse D1 requires a minimum of 20 units and a maximum of 40 units. Warehouse D2 requires a minimum of 20 units and, over and above, it can take as much as can be supplied. A balanced transportation problem is to be formulated for the above situation. The number of supply points, the number of demand points, and the total supply (or total demand) in the balanced transportation problem respectively are A) 2, 4, 90 B) 2, 4, 110 C) 3, 4, 90 D) 3, 4, 110 Answer : (C) 5 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is A) 0.651 x 10-3 B) 0.651 C) 6.51 D) 0.651 x 103 Answer : (B) 6 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation? A) N010 G02 X10 Y10 X5 Y5 R5 B) N010 G03 X10 Y10 X5 Y5 R5 C) N010 G01 X5 Y5 X10 Y10 R5 D) N010 G02 X5 Y5 X10 Y10 R5 Answer : (D) 7 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed. All cylinders firing 3037 kW Number 1 cylinder not firing 2102 kW Number 2 cylinder not firing 2102 kW Number 3 cylinder not firing 2100 kW Number 4 cylinder not firing 2098 kW The mechanical efficiency of the engine is A) 91.53% B) 85.07% C) 81.07% D) 61.22% Answer : (C) 8 In terms of theoretical stress concentration factor (Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ‘q’ is expressed as A) (Kf -1) (Kt -1) B) (Kf -1) (Kt +1) C) (Kt -1) (Kf -1) D) (Kf +1) (Kt +1) Answer : (A) 9 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as A) x1 = 0.5 B) x1= 1.406 C) x1= 1.5 D) x1 = 2 Answer : (C) 10 The S-N curve for steel becomes asymptotic nearly at A) 103 cycles B) 104 cycles C) 10 6 cycles D) 10 9 cycles Answer : (C) 11. In PERT analysis a critical activity has A) maximum Float B) zero Float C) maximum Cost D) minimum Cost Answer : (B) 12 Environment friendly refrigerant R134a is used inthe new generation domestic refrigerators. Itschemical formula is A) CH C1 F2 B) C2 C13 F3 C) C2 C12 F4 D) C2 H2 F4 Answer : (D) 13 A solid cylinder (surface 2) is located at the centreof a hollow sphere (surface 1). The diameter of the sphere is 1m, while the cylinder has a diameter and length of 0.5 m each. The radiation configuration factor F11 is A) 0.375 B) 0.625 C) 0.75 D) 1 Answer : (C) 14 For a fluid flow through a divergent pipe of length L having inlet and outlet radii of R1 and R2 respectively and a constant flow rate of Q, assuming the velocity to be axial and uniform at any cross-section, the acceleration at the exit is A) 2Q(R1 - R2) p LR23 B) 2Q2 (R1 - R2) p LR23 C) 2Q2 (R1 - R2) p2LR25 D) 2Q2 (R2 - R1) p2LR25 Answer : (C) 15 An incompressible fluid (kinematic viscosity, 7.4 x 10-7 m2/s, specific gravity, 0.88) is held between two parallel plates. If the top plate is moved with a velocity of 0.5 m/s while the bottom one is held stationary, the fluid attains a linear velocity profile in the gap of 0.5 mm between these plates; the shear stress in Pascals on the surface of top plate is A) 0.651 x 10-3 B) 0.651 C) 6.51 D) 0.651 x 103 Answer : (B) 16 The tool of an NC machine has to move along a circular arc from (5,5) to (10,10) while performing an operation. The centre of the arc is at (10,5). Which one of the following NC tool path commands performs the above mentioned operation? A) N010 G02 X10 Y10 X5 Y5 R5 B) N010 G03 X10 Y10 X5 Y5 R5 C) N010 G01 X5 Y5 X10 Y10 R5 D) N010 G02 X5 Y5 X10 Y10 R5 Answer : (D) 17 During a Morse test on a 4 cylinder engine, the following measurements of brake power were taken at constant speed. All cylinders firing 3037 kW Number 1 cylinder not firing 2102 kW Number 2 cylinder not firing 2102 kW Number 3 cylinder not firing 2100 kW Number 4 cylinder not firing 2098 kW The mechanical efficiency of the engine is A) 91.53% B) 85.07% C) 81.07% D) 61.22% Answer : (C) 18 In terms of theoretical stress concentration factor(Kt) and fatigue stress concentration factor (Kf ), the notch sensitivity ‘q’ is expressed as A) (Kf -1) (Kt -1) B) (Kf -1) (Kt +1) C) (Kt -1) (Kf -1) D) (Kf +1) (Kt +1) Answer : (A) 19 Starting from x0 = 1, one step of Newton-Raphson method in solving the equation x3 + 3x -7 = 0 gives the next value (x1) as A) x1 = 0.5 B) x1= 1.406 C) x1= 1.5 D) x1 = 2 Answer : (C) 20 A maintenance service facility has Poisson arrival rates, negative exponential service time and operates on a ‘first come first served’ queue discipline. Break downs occur on an average of 3 per day with a range of zero to eight. The maintenance crew can service an average of 6 machines per day with a range of zero to seven. The mean waiting time for an item to be serviced would be A) 16 day B) 13 day C) 1 day D) 3 days Answer : (A) 21 The S-N curve for steel becomes asymptotic nearly at A) 103 cycles B) 104 cycles C) 106 cycles D) 109 cycles Answer : (C) 22 In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be A) 5 mm B) 39 mm C) 78mm D) 120mm Answer : (A) 23 Water at 42°C is sprayed into a stream of air at atmospheric pressure, dry bulb temperature of 40°C and a wet bulb temperature of 20°C. The air leaving the spray humidifier is not saturated. Which of the following statements is true? A) Air gets cooled and humidified B) Air gets heated and humidified C) Air gets heated and dehumidified D) Air gets cooled and dehumidified Answer : (B) 24 The angle between two unit-magnitude coplanar vectors P(0.866, 0.500,0) and Q(0.259, 0.966,0) will be A) 0° B) -30° C) 45° D) 60° Answer : (C) 25 A lot has 10% defective items. Ten items are chosen randomly from this lot. The probability that exactly 2 of the chosen items are defective is A) 0.0036 B) 0.1937 C) 0.2234 D) 0.3874 Answer : (B) 26 Stokes theorem connects A) a line integral and a surface integral B) a surface integral and a volume integral C) a line integral and a volume integral D) gradient of a function and its surface integral Answer : (A) 27 A solar collector receiving solar radiation at the rate of 0.6 k W/m2 transforms it to the internal energy of a fluid at an overall efficiency of 50%. The fluid heated to 350 K is used to run a heat engine which rejects heat at 313 K. If the heat engine is to deliver 2.5 kW power, the minimum area of the solar collector required would be A) 8.33m2 B) 16.66m2 C) 39.68m2 D) 79.36m2 Answer : (D) 28 When the temperature of a solid metal increases, A) strength of the metal decreaes but ductility increases B) both strength and ductility of the metal decrease C) both strength and ductility of the metal increase D) strength of the metal increases but ductility decreases Answer : (A) 29 A company produces two types of toys: P and Q. Production time of Q is twice that of P and the company has a maximum of 2000 time units per day. The supply of raw material is just sufficient to produce 1500 toys (of any type) per day. Toy type Q requires an electric switch which is available @ 600 pieces per day only. The company makes a profit of Rs. 3 and Rs. 5 on type P and Q respectively. For maximization of profits, the daily production quantities of P and Q toys should respectively be A) 100, 500 B) 500, 1000 C) 800, 600 D) 1000, 1000 Answer : (C) 30 A spherical thermocouple junction of diameter 0.706 mm is to be used for the measurement Aof temperature of a gas stream. The convective heat transfer co-efficient on the bead surface is 400 W/m2K. Thermophysical properties of thermocouple material are k = 20 W/mK, C = 400 J/kg K and r = 8500 kg/m3. If the thermocouple initially tot 30°C is placed in a hot stream of 300°C, the time taken by the bead to reach 298°C, is A) 2.35 s B) 4.9 s C) 14.7 s D) 29.4 s Answer : (B) 31 In a spring-mass system, the mass is 0.1 kg and the stiffness of the spring is 1 kN/m. By introducing a damper, the frequency of oscillation is found to be 90% of the original value. What is the damping coefficient of the damper? A) 1.2 N.s/m B) 3.4 N.s/m C) 8.7 N.s/m D) 12.0 N.s/m Answer : (C) 32.In a machining operation, doubling the cutting speed reduces the tool life to 1/8 of the original value. The exponent n in Taylor A) 1/8 B) 1/4 C) 1/3 D) 1/2 Answer : (C) 33.In a rolling process, sheet of 25 mm thickness is rolled to 20 mm thickness. Roll is of diameter 600 mm and it rotates at 100 rpm. The roll strip contact length will be A) 5 mm B) 39 mm C) 78 mm D) 120 mm Answer : (A) 34.A soldering operation was work-sampled over two days (16 hours) during which an employee soldered 108 joints. Actual working time was 90% of the total time and the performance rating was estimated to be 120 percent. If the contract provides allowance of 20 percent of the total time available, the standard time for the operation would be A) 8 min B) 8.9 min C) 10 min D) 12 min Answer : (D) 35. A welding operation is time-studied during which an operator was pace-rated as 120%. The operator took, on an average, 8 minutes for producing the weld-joint. If a total of 10% allowances are allowed for this operation, the expected standard production rate of the weld-joint (in units per 8 hour day) is A) 45 B) 50 C) 55 D) 60 Answer : (A) |
| 25th July 2014 10:20 AM | |
| Unregistered | Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers Will you please share with me the Oil and Natural Gas Corporation Limited Mechanical Engineering last year papers? |
