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Wednesday, 23 January 2013

Manufacturing process-III-model question paper for B.E/B.Tech engineering

1(a) Differentiate between Hot working, Cold working and Warm working. (6 Marks)
(b) What are residual stresses in wrought products? (4 Marks)
(c) Write a note on deformation of metals. (4 Marks)
(d) Explain in detail the influencing parameters in metal working process. (6 Marks)
2(a) What is hydrostatic stress. Write a note on its influence on metal working process. (6 Marks)
(b) Represent 3D principal stresses and their planes. (6 Marks)
(c) Prove that soct=mean of three principal stresses. (4 Marks)
(d) The state of stress at a point in a material is given by sx=80Mpa. sy =100MPa and τxy=60MPa. If the Y.S of the material is 150 MPa, determine whether yielding of the material will occur or not according to Trescas or Von Mises Criteria. (4 Marks)
3(a) Write a note on defects in forged products. (4 Marks)
(b) What are the assumptions made in open die forging? (4 Marks)
(c) With the help of neat sketches, explain the working of steam hammer and board hammer. (6 Marks)
(d) An Aluminium billet 24mm × 32 mm height is compressed between flat parallel anvils to a height of 15 mm. Determine the frictionless W.D Take average Y.S of the material = 54 KN/mm2. If m=1.4, find the maximum load exerted on the material. (6 Marks)
4(a) Derive the necessary minimum condition for rolling. (6 Marks)
(b) What is the effect of external load on the Roll radius? (4 Marks)
(c) Write a note on Rolling of structural shapes. (6 Marks)
(d) If the maximum reduction in rolling of slab is from 25mm to 15mm, calculate the value of coefficient of friction. Take the roll diameter as 750 mm. Also find the length of projection of arc of contact. (4 Marks)
5(a) Differentiate between Direct and Indirect extrusion process. (6 Marks)
(b) How is extrusion pressure and extrusion ratio related as a function of billet temperature? Explain. (6 Marks)
(c) Write a note on defects in extrusion products. (4 Marks)
(d)  What are the applications of extruded products? (4 Marks)
6(a) Explain drawing ratio. What is the maximum reduction in area that is possible in drawing for one pass? (6 Marks)
(b) Explain the different methods available for tube drawing. (6 Marks)
(c) What is the maximum reduction possible per pass in drawing Aluminium rod through a die of semi die angle 360,m=0.01. (8 Marks)
7(a) Explain the operation of a die-punch assembly using a neat sketch. (4 Marks)
(b) What are the basic operating parameters in a press? (4 Marks)
(c) What are the different HERF methods? Explain. (8 Marks)
(d) A blanking die is used for handling blanks of 150mm dia on 3mm thick M.S.sheet. Blanking takes place in 0.25 sec. Find the power required for driving motor. Take shear strength of the sheet=400MPa. (4 Marks)
8(a) What are the advantages and limitations of powder metallurgy? (4 Marks)
(b) Explain how blending of powder is carried out? What is its significance? (6 Marks)
(c) Explain the mechanism involved in sintering. (4 Marks)
(d) Distinguish between cold isostatic pressing and hot isostatic pressing. (6 Marks)

Friday, 11 January 2013

Internal combustion engines – for B.E/B.Tech model question paper

1(a) Explain with suitable sketches, the working of a four-stroke spark-ignition engine. (6 Marks)
(b) Define mean effective pressure. What is its relevance in reciprocating engines? (4 Marks)
(c) What are the characteristics of constant volume fuel-air cycle? (6 Marks)
(d) A diesel engine develops 5 kW. Its indicated thermal efficiency is 30% and mechanical efficiency 57%. Estimate the fuel consumption of engine in (a) kg/hr, (b) litres/hr, (c) indicated specific fuel consumption, and (d) brake specific fuel consumption. (4 Marks)
2(a) Explain the term ‘burning time loss’ with the help of p-V diagram. (4 Marks)
(b) Discuss the general principles of SI engine combustion chamber design. (6 Marks)
(c) Discuss the variables affecting the delay period. (4 Marks)
(d) In a bomb calorimeter test on petrol, the HCV was determined and found to be 46900 kJ/kg. If the fuel contains 14.4% H2 by mass, calculate the LCV. Given ufg at 250C for H2O = 2304.4 kJ/kg. (4 Marks)
3(a) What are the factors which affect the process of carburetion? (4 Marks)
(b) Distinguish between continuous injection system and timed injection system. (6 Marks)
(c) Compare the burning rates in petrol and diesel engines. (4 Marks)
(d) A 6-cylinder 4-stroke S.I. engine having a piston displacement of 700 cm3 per cylinder developed 78 kW at 3200 r.p.m and consumed 27 kg of petrol per hour. The calorific value of petrol is 44 MJ/kg. Estimate the volumetric efficiency of the engine if the air-fuel ratio is 12 and the intake air is 0.9 bar, 320C.  Also determine the brake thermal efficiency and the brake torque. (6 Marks)
4(a) Describe a battery ignition system with the help of a sketch. (6 Marks)
(b) What is a Texaco ignition system? Mention its advantages. (4 Marks)
(c) What is the significance of flash and fire points of a lubricant. (6 Marks)
(d) A petrol engine with indicated thermal efficiency of 30% has an fp of 18 at 1500 rev/min and 45 kW at 2500 rev/min. If the bhp required at each speed is 75 kw and the calorific value of the fuel is 44000 kJ/kg, calculate the bsfc at both speeds, assuming indicated thermal efficiency to be same at both speeds. (4 Marks)
5 (a) Why is over-cooling in an engine harmful? (4 Marks)
(b) Describe with a sketch the construction and working of a thermostat. (6 Marks)
(c) Explain the scavenging process in two-stroke engine. What is meant by blowdown? (6 Marks)
(d) Explain pulse turbocharging. (4 Marks)
6 (a) Describe with a sketch, the principle of eddy current dynamometer. (6 Marks)
(b) What are reduction mechanisms for taking indicator diagrams? Describe with sketches the important types of reduction mechanisms. (6 Marks)
(c) What is a flame ionization detector? (4 Marks)
(d) A test on a two-stroke single cylinder oil engine gave the following results: Cylinder bore=200 mm, engine stroke=250 mm, indicated mean effective pressure=4.5×102 N/m2, fuel consumption=7kg/h, calorific value of fuel=43500 kJ/kg, engine speed=180 rev/min. Calculate the indicated power and indicated thermal efficiency. (4 Marks)
7 (a) Describe with a sketch, a dual-fuel engine and comment on its performance. (6 Marks)
(b) Discuss the performance of multi-fuel engine on various fuels. (4 Maks)
(c) What is meant by crankcase blowby? How it can be controlled? (6 Marks)
(d) Compare diesel engine and gasoline engine emissions. (4 Marks)
8 (a) What are the important methods of charge stratification? (4 Marks)
(b) Discuss with the help of a sketch, the governance of Stirling engine. (6 Marks)
(c) Discuss some applications of Wankel RC engine. (4 Marks)
(d) A gas turbine cycle takes in air at 250C and atmospheric pressure. The compression pressure ratio is 4. The compressor efficiency is 75%. The inlet temperature to turbine is limited to 7500C. What turbine efficiency would give overall cycle efficiency 0%.  (4 Marks)

Friday, 4 January 2013

Mechatronics-Model question paper for B.E/B.Tech/M.E/M.Tech/PhD

1(a) Write a note on microprocessor based controllers. (4 Marks)
(b) Explain with the help of a block diagram, the working of engine management controller. (8 Marks)
(c) Explain different cycles of operation of automatic washing machine. (8 Marks)
2(a) Write a note on classification of sensors. (4 Marks)
(b) Distinguish between linear and threshold Hall Effect sensors. Mention their advantages and disadvantages. (6 Marks)
(c) Explain the construction, working and applications of photodiodes. (6 Marks)
(d) With a neat sketch, explain the working of ultrasonic proximity sensor. (4 Marks)
3(a) Mention some applications of hydraulic cylinders. (4 Marks)
(b) Explain the working of swash plate motor. (4 Marks)
(c) Distinguish between sequence valve and check valve. (6 Marks)
(d) What is hydrostatic transmission? Explain. (6 Marks)
4(a) With the help of a neat sketch, explain the arrangement and working of a limit switch. (6 Marks)
(b) Explain the working of a triac as a switch. Draw triac characteristics. (6 Marks)
(c) What is a Darlington pair? Mention its important applications. (4 Marks)
(d) Explain the working of a servomotor with the help of a block diagram. (4 Marks)
5(a) Explain using necessary equations, the design of a spring mass-damper system. (6 Marks)
(b)Write a note on modeling of actuators. (6 Marks)
(c) Explain the concepts thermal resistance and thermal capacitance. (4 Marks)
(d) Write a note on modeling of thermal systems. (4 Marks)
6(a) Mention some important requirements for good guide ways. (4 Marks)
(b) Explain stick-slip phenomena. (4 Marks)
(c) Differentiate between hydrostatic slide ways and hydrodynamic slide ways. (6 Marks)
(d) Write a note on spindles and spindle bearings. (6 Marks)
7(a) Mention merits and demerits of antifriction bearings. (4 Marks)
(b) What is an operational amplifier? How it is used as Schmitt trigger amplifier? (8 Marks)
(c) Distinguish between band pass filters and band stop filters. (4 Marks)
(d) Explain the working of successive approximation ADC. (4 Marks)
8(a) Write a note on binary system and hexadecimal system. (6 Marks)
(b) Draw graphical symbol and truth table of NAND gate. What is its Boolean equation? (4 Marks)
(c) What are the four types of ROM. (4 Marks)
(d) Explain the classification of microcontrollers. (6 Marks)