Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Winter 1st And 2nd Sem New And Spfu 3110006 Basic Mechanical Engineering Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? I & II (NEW) EXAMINATION ? WINTER 2019
Subject Code: 3110006 Date: 03/01/2020
Subject Name: Basic Mechanical Engineering
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of steam tables is allowable
Marks
Q.1 (a) Define prime movers. Write any Four examples of the prime movers. 03
(b) Define the terms: Hardness, Toughness, Ductility, Elasticity
04
(c) List the non-convectional sources of energy. Prepare a short note on solar
energy.
07
Q.2 (a) Distinguish between coupling and clutch. 03
(b) Describe briefly using neat diagrams the types of belt drives. 04
(c) Explain with neat sketch the Vapor Compression Refrigeration system. Also
draw p-h and T-s diagram for the same.
07
OR
(c) Classify Air Compressors. Explain construction and working of centrifugal
pump with sketch.
07
Q.3 (a) Prove that the difference between two specific heats of gases is equal to its
characteristic gas constant.
03
(b) Differentiate between gas constant and Universal gas constant. 04
(c) One kg of gas at a pressure of 100 kPa and temperature of 17 ?C is compressed
isothermally in a piston-cylinder arrangement to final pressure of 2500 kPa.
The characteristic gas equation is given by the relation pV = 260 T per kg
where T is in Kelvin. Find out (1) Final Volume (2) Compression Ratio (3)
Change in enthalpy (4) Work done on the gas.
07
OR
Q.3 (a)
One kg gas is compressed adiabatically by following the law pV
?
= C from
initial temperature of 290K.The initial pressure of gas is 1 bar. The initial and
final volumes of gas are 0.50 m
3
and 0.05 m
3
respectively. Find the final
temperature and pressure of gas. Assume ?=1.4
03
(b) Write the uses of ?Steam Tables? 04
(c) Find the internal energy of 1 kg of steam at a pressure of 15 bar when steam is
(1) Super-heated at a temperature of 400 ?C and (2) Wet with dryness fraction
of 0.9. Take specific heat of superheated steam as 2.1 kJ/kg-K.
07
Q.4 (a) A diesel engine works on Diesel cycle with a compression ratio of 15 and cut
off ratio of 1.75. Calculate the air standard efficiency. Assume ?= 1.4.
03
(b) Derive the equation for air standard efficiency of Otto cycle. 04
(c) The following readings were observed during a test on Two Stroke Single
Cylinder Diesel engine:
Bore = 22 cm
Stoke = 28 cm
Speed = 350 rpm
07
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Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ? I & II (NEW) EXAMINATION ? WINTER 2019
Subject Code: 3110006 Date: 03/01/2020
Subject Name: Basic Mechanical Engineering
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Use of steam tables is allowable
Marks
Q.1 (a) Define prime movers. Write any Four examples of the prime movers. 03
(b) Define the terms: Hardness, Toughness, Ductility, Elasticity
04
(c) List the non-convectional sources of energy. Prepare a short note on solar
energy.
07
Q.2 (a) Distinguish between coupling and clutch. 03
(b) Describe briefly using neat diagrams the types of belt drives. 04
(c) Explain with neat sketch the Vapor Compression Refrigeration system. Also
draw p-h and T-s diagram for the same.
07
OR
(c) Classify Air Compressors. Explain construction and working of centrifugal
pump with sketch.
07
Q.3 (a) Prove that the difference between two specific heats of gases is equal to its
characteristic gas constant.
03
(b) Differentiate between gas constant and Universal gas constant. 04
(c) One kg of gas at a pressure of 100 kPa and temperature of 17 ?C is compressed
isothermally in a piston-cylinder arrangement to final pressure of 2500 kPa.
The characteristic gas equation is given by the relation pV = 260 T per kg
where T is in Kelvin. Find out (1) Final Volume (2) Compression Ratio (3)
Change in enthalpy (4) Work done on the gas.
07
OR
Q.3 (a)
One kg gas is compressed adiabatically by following the law pV
?
= C from
initial temperature of 290K.The initial pressure of gas is 1 bar. The initial and
final volumes of gas are 0.50 m
3
and 0.05 m
3
respectively. Find the final
temperature and pressure of gas. Assume ?=1.4
03
(b) Write the uses of ?Steam Tables? 04
(c) Find the internal energy of 1 kg of steam at a pressure of 15 bar when steam is
(1) Super-heated at a temperature of 400 ?C and (2) Wet with dryness fraction
of 0.9. Take specific heat of superheated steam as 2.1 kJ/kg-K.
07
Q.4 (a) A diesel engine works on Diesel cycle with a compression ratio of 15 and cut
off ratio of 1.75. Calculate the air standard efficiency. Assume ?= 1.4.
03
(b) Derive the equation for air standard efficiency of Otto cycle. 04
(c) The following readings were observed during a test on Two Stroke Single
Cylinder Diesel engine:
Bore = 22 cm
Stoke = 28 cm
Speed = 350 rpm
07
2
Net brake load = 65 kg
Effective brake drum diameter = 100 cm
Mean Effective Pressure = 3 bar
Fuel consumption = 4 kg/h
Calorific value of fuel = 43 MJ
Calculate: (1) Indicated Power (2) Brake Power (3) Mechanical Efficiency (4)
Brake thermal Efficiency
OR
Q.4 (a) Classify I.C. Engines. 03
(b) Determine the brake thermal efficiency of an engine with following data:
Brake Power = 80 kW
Fuel consumption rate = 20 kg/hour
Calorific value of the fuel = 43 MJ/kg
04
(c) Discuss the construction and working of four stroke Petrol engines. 07
Q.5 (a) Define the terms ?Refrigeration?, ?Ton of Refrigeration? and ?Coefficient of
Performance?
03
(b) What is boiler? Compare fire tube boiler with water tube boiler. 04
(c) Explain with neat sketch, the construction and working of
(1) Fusible plug (2) Air preheater.
07
OR
Q.5 (a) Differentiate between reciprocating compressor and rotary compressor. 03
(b) Differentiate between boiler mountings and accessories. 04
(c) Discuss the construction details and working of Cochran boiler with neat
sketch.
07
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This post was last modified on 20 February 2020