Automobile Engineering Model Question Paper : www.annauniv.edu Anna University

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B.E. DEGREE EXAMINATION.
Fourth Semester
Automobile Engineering
AT 235 — AUTOMOTIVE PETROL ENGINES

Answer ALL questions.
PART A — (10 ? 2 = 20 marks)
1. List out eight important parts of 4 stroke petrol engine.
2. Write the firing order of four cylinder and six cylinder engine and its significance.
3. List out the functions of carburetion.
4. Sketch the cut–sectional view of Electrical Pump.

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www.annauniv.edu/academic/m040.doc

5. List four required properties of a good coolant.
6. What are the various types of lubrication systems?
7. Mention four important engine variables on Engine–knock.
8. Sketch four types of combustion chamber.
9. Name various types of two stroke engines.
10. List out various types of scavenging pumps.

PART B — (5 ? 16 = 80 marks)
11. Compare by way of tabulation the differences between four stroke and two stroke engine.
12. (a) Sketch and explain the working principle of carburettor involving starting, idling and acceleration circuits. (10)
Or
(b) A petrol engine consumes 6.8 kg of petrol per hour. The specific gravity of the fuel 0.7 and its temperature 32?C. The air fuel ratio is 15. The choke tube has a diameter of 20 mm. Calculate the diameter of the single jet of the carburettor if the top of the jet is 5 mm above the petrol level in the float chamber. R of air can be assumed. (6)
13. (a) (i) Why we need a cooling system in Engines? (6)
(ii) Sketch and explain Mist lubrication system. (10)
Or
(b) (i) List the essential properties of lubricant used in vehicles. (6)
(ii) Explain with sketch the thermosyphen cooling system. (10)
14. (a) Sketch and explain various stages of combustion in SI engines.
Or
(b) (i) Define the term knock and abnormal combustion. (6)
(ii) List the factors controlling combustion chamber design. (10)
15. (a) Sketch and explain the working of any two types of two stroke engine.
(2 ? 8 = 16)
Or
(b) What are the various scavenging methods? (sketch and explain).

B.E. DEGREE EXAMINATION.
Fourth Semester
Instrumentation Engineering
IT 240 — INSTRUMENTATION COMPONENTS

Answer ALL questions.
PART A — (10 ? 2 = 20 marks)
1. List the various types of Instrumentation components.
2. State the relative merits of pulleys and gears.
3. Bring out the difference between Gate valve and diaphram valve.
4. List out the advantages and disadvantages of pneumatic relays.
5. Define Power rating of a resistor.
6. List the types of fixed resistors.
7. Explain the function of LDR.
8. With neat diagram explain the principle of opto coupler.
9. Define the term ‘transformation ratio’ of a transformer.
10. Bring out the difference between relays and switches.

PART B — (5 ? 16 = 80 marks)
11. (i) What are the types of gears? Explain how tight gearing without backlash can be achieved. (6)
(ii) Explain the principle and applications of Geneva mechanism. (6)
(iii) With neat diagram explain any two types of mechanical Indicating Mechanisms. (4)
12. (a) (i) With neat diagram explain the construction and working principle
of flapper nozzle. (6)
(ii) Discuss its response curve. (3)
(iii) What are the factors to be considered for selecting a control valve. (7)
Or
(b) (i) With neat diagram explain the operation of pneumatic actuator
with and without positioner. (10)
(ii) Discuss the disadvantages of pneumatic actuator without positioner and also explain how it is eliminated in with positioner scheme. (6)
13. (a) With neat diagram explain the construction, working principle and application of a magnetic amplifier. (6 + 8 + 2)
Or
(b) (i) Explain the construction of a variable reluctance stepper motor. (4)
(ii) Derive the torque equation of the stepper motor. (8)
(iii) Explain the application of stepper motor in open loop mode. (4)
14. (a) (i) Explain the construction and characteristics of thermistor. (6)
(ii) Explain the application of thermistor in
(1) Level measurement.
(2) Temperature Compensation. (10)
Or
(b) (i) With neat diagram explain the construction and working principle of SCR. (10)
(ii) Explain how SCR is used in power control application. (6)
15. (a) (i) Explain the construction, working principle and application of PIN
diode. (6)
(ii) Bring out the difference between Dispersion and Reflection prism.
(5)
(iii) Explain the working of LED. (5)
Or
(b) (i) Explain the term grating and discuss its application. (8)
(ii) Write short notes on resonators and reflectors. (8)