Download GTU BE/B.Tech 2019 Summer 1st Sem And 2nd Sem Old 110006 Elements Of Mechanical Engineering Question Paper

Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 1st Sem And 2nd Sem Old 110006 Elements Of Mechanical Engineering Previous Question Paper

1
Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY

BE - SEMESTER ?I &II (OLD) EXAMINATION ? SUMMER-2019
Subject Code: 110006 Date: 04/06/2019

Subject Name: Elements Of Mechanical Engineering

Time: 10:30 AM TO 01:00 PM Total Marks: 70

Instructions:

1. Attempt any five questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What is refrigeration? Explain working of vapour compression refrigeration
cycle. Name the basic components of VCRC
07
(b) What is Adiabatic process? Prove with usual notations the governing equation
for adiabatic process PV
?
= Constant
07

Q.2 (a) Calculate the enthalpy per kg of steam at 10 bar pressure and a temperature of
300 ?C. Find also the change in enthalpy if this steam is expanded to 1.4 bar and
dryness fraction of 0.8. Take specific heat of superheat steam equal to 2.29
kj/kgK.
07
(b) Define (i) Hardness (ii) Creep (iii) Resilience (iv) Toughness (v) Sensible heat
(vi) Latent heat (vii) Dryness fraction.
07

Q.3 (a) With usual notations derive an expression for work done for single stage single
acting reciprocating air compressor by considering clearance volume.
07
(b) State the function of (i) Fusible Plug (ii) Economiser (iii) Safety valves (iv)
water level indicator (v) Superheater (vi) Pressure gauge (vii) Air pre-heater
07

Q.4 (a) Define the following terms related to belt drive: (i) Velocity ratio (ii) Initial
Tension (iii) Slip (iv) Creep (v) Power transmitted in belt drive
07
(b) In ideal constant volume cycle the pressure & temperature at the beginning of
compression are 97 KPa & 50? C respectively. The volume ratio is 8. The heat
is supplied during the cycle is 930 kJ/kg of working fluid. Calculate: (i) The
maximum temperature attained in the cycle. (ii) The thermal efficiency of cycle.
(iii) Work done during the cycle /kg of working fluid.
07

Q.5 (a) List various liquid fuels. State their merits over solid fuels. 04
(b) What is priming? Why it is required in centrifugal pump? 03
(c) Explain with neat sketch construction and working of two stroke petrol engine 07

Q.6 (a) Differentiate between Fire tube and Water tube boiler. 03
(b) Explain working of Hartnell Governor with neat sketch 04
(c) Following readings were taken during test of single cylinder four stoke oil
engine. (i) Cylinder diameter = 250 mm (ii) Stroke length = 400 mm (iii) Main
effective pressure = 6.5 bar (iv) Engine speed = 250 r. p .m. (v) Net load on
brake = 1080 Newton (vi) Effective diameter of brake = 1.5 meter (vii) Fuel
used per hour = 10 Kg (viii) Calorific value of fuel = 44300 KJ/Kg Calculate
(1) Indicated power, (2) Brake power, (3) Mechanical efficiency and (4)
Indicated thermal efficiency.
07

Q.7 (a) Define Zeroth law, First law and Second law of thermodynamics. Give
limitations of first law of thermodynamics
07
(b) Discuss construction, Specification and working of Cochran boiler with sketch. 07

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