Scheme – E
Sample Question Paper
Course Name : Diploma in Automobile Engineering
Course Code : AE
Semester
: Fourth
Subject Title : Automobile Engines
12097
Marks
Time: 3 Hours
: 100
Instructions:
1] All questions are compulsory.
2] Figures to the right indicate full marks.
3] Use of non-programmable calculator is permissible.
4] Illustrate your answer with neat sketches wherever necessary.
5] Preferably, write the answers in sequential order.
Q.1 (A) Attempt any SIX of the following:
(6 x 2 = 12)
a) Define Stroke.
b) State two functions of a Gasket.
c) Why cooling system is required in an I. C. Engine?
d) Define Indicated Power.
e) List 2 functions of a carburetor.
f) What is the need of lubrication for an engine?
g) When choke is used and why?
h) Why additives are added in lubricants?
Q.1 (B) Attempt any TWO of the following:
(2 x 4 = 08)
a) Classify I.C. Engines on the basis of Number of Strokes, Number of cylinders,
Fuel used and Camshaft position.
b) Explain the working of 4 stroke C. I. Engine.
c) Draw a labeled sketch of pintle and pintaux type nozzles.
Q.2 Attempt any FOUR of the following:
(4 x 4=16)
a) Which are the material is used for manufacturing? Identify & label the component
shown below.
Fig No. 1
b) Explain with neat sketch the working of Overhead Valve Mechanism.
c) State the application and advantage of dry and wet liners.
d) Classify lubricating oils on the basis of viscosity and service rating.
e) Draw neat labeled sketch of compression and oil ring.
f) State different parts of cooling system and explain function of any one.
Q.3 Attempt any Two of the following:
(2 x 8=16)
a) With neat sketch explain the working of electric fuel pump.
b) Draw neat labeled sketch of actual valve timing diagram for 4-stroke S.I and C.I.
engine.
c) i) What are the mixture requirements for transient conditions.
ii) Explain the circuit of a carborettor.
Q.4 Attempt any Four of the following:
(4 x 4=16)
a) Draw a neat labeled sketch of reed valve and explain its working
b) Draw a neat-labeled sketch of simple carburetor.
c) What is the effect of running a vehicle without pressure cap on radiator, on the
following parameters i) coolant condition, ii) charge formation, iii) fuel
consumption, iv) operational difficulty.
d) State necessity of thermostat. Mention two types of thermostat.
e) Distinguish between S.I. and C.I. engines on the basis of i) fuel used, ii)
Compression ratio, iii) weight, iv) application.
Q.5 Attempt any FOUR of the following:
(4 x 4=16)
a) Explain the working of mechanical fuel pump used in fuel supply system.
b) What is B.S.F.C.? Give its significance.
c) Why it is necessary to add additives in coolant. Name two important types of
additives.
d) Define compression ratio. State the range of compression ratio for S.I. and C.I.
engines.
e) Draw a labeled sketch indicating the nomenclatures of an I.C. engine.
f) Why spark plug is not used in diesel engines? Mention the method of ignition used
for S.I. and C.I. engines.
Q.6 Attempt any TWO of the following:
(2 x 8=16)
a) Following readings were noted during a test on a single cylinder 2-stroke diesel
engine. Engine is motored by an electric motor and frictional power loss recorded
on Wattmeter is 1.5 KW.
Net brake load = 227 N
Diameter of Brake wheel = 100 cm
Engine Speed = 500 rpm
Fuel consumption = 2.04 Kg/ hr.
Calorific value of fuel = 42000 KJ/kg
Find Mechanical efficiency and brake thermal efficiency.
b) An engine develops a brake power of 26.2 KW. Following observations are made
during a trial.
Power required to motor the engine = 4.5 KW
Cooling water circulated = 7.5 Kg/ min.
Specific heat capacity of Water = 4.187 KJ/kg k
Petrol consumption = 200 gm/ min
Temperature rise of cooling water = 50 ºC.
If calorific value of petrol is 46000 KJ/kg, draw the heat balance chart for the test
on KJ/Min basis.
c) For the same power output size of the diesel engine is bigger than the petrol engine.
Justify the statement with the help of different parameters.