Download PTU B.Tech 2021 Jan AE 5th Sem 78227 Automotive Petrol And Diesel Engines Question Paper

Download PTU (Punjab Technical University) B.Tech (Bachelor of Technology) / BE (Bachelor of Engineering) 2021 January AE 5th Sem 78227 Automotive Petrol And Diesel Engines Previous Question Paper

Roll No.
Total No. of Pages : 02
Total No. of Questions : 18
B.T ech. (Automo bile Engineering) (Sem.?5)
AUTOMOTIVE PETROL AND DIESEL ENGINES
Subject Code : BTAE503-18
M.Code : 78227
Time : 3 Hrs. Max. Marks : 60
INST RUCT ION TO CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Answer briefly :
1)
Sketch P-V and T-S diagram of Diesel cycle.
2)
Define air standard efficiency.
3)
Define Octane and Cetane number.
4)
Why very rich mixture is required for Idling?
5)
Discuss the requirements of an Ideal injection.
6)
Define mean effective pressure and stoichiometric air fuel ratio.
7)
Explain the function of combustion chamber.
8)
What are two basic types of internal combustion engines?
9)
Why supercharging of CI engines is done?
10) List a few anti-knock agents commonly added to gasoline.
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SECTION-B
11) Define and explain the relation between :
a. Mechanical efficiency
b. Brake thermal efficiency.
12) An engine working on Otto cycle has the following conditions: Pressure at the beginning
of compression is 1 bar and pressure at the end of compression is 11 bar. Calculate the
compression ratio and air-standard efficiency of the engine. Assume = 1.4.
13) Compare SI and CI engines with respect to :
a. basic cycle
b. compression ratio
c. fuel used
d. fuel injection
14) Discuss the effect of spark advance on the performance of an Otto cycle engine. What is
meant by the optimum spark advance?
15) How does exhaust temperature and mean effective pressure affect the engine
performance? Explain.
SECTION-C
16) A petrol engine working on Otto cycle has an maximum pressure of 50 bar. Heat supplied
is 1000 kJ/kg. If the pressure ratio during compression 12.286, find the compression ratio
and also the ratio of peak temperature to inlet temperature. Take p1 = 1 bar and
T1 = 27 C.
17) Draw the Carnot cycle on p-V and T -s diagrams. Derive an expression for its efficiency.
Comment on the significance of this result as it related to source and sink temperature.
18) "Factors tending to increase detonation in SI engines tend to reduce knock in CI engines"
Comment on this statement considering delay period and flames front speed.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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