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Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
PDDC SEMESTER-I EXAMINATION WINTER 2018
Subject Code:X11102 Date: 09/01/2019
Subject Name: Elements of Mechanical And Structural 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

Define prime mover. List out the different sources of energy. Write down the first law of thermodynamics.
07

Explain Carnot cycle on p-v diagram. Find the efficiency of Carnot cycle.
07
Q.2

What are the function of flywheel? Explain quality and quantity type governing for I.C. Engine.
07

Enlist various uses of air compressor. What are the importances of Multistage reciprocating compressors?
07
Q.3

The following readings were recorded during the test on single cylinder four stroke diesel engine.
(1)Cylinder diameter 250 mm
Stroke length 350 mm
Mean effective pressure 6.7 bar
Speed of engine 250 r.p.m.
Net brake load 1070 N
Effective brake drum diameter 1.5 m
Fuel consumption rate 10 kg per hour.
C.V. of the fuel 44300 kJ/kg.
Calculate: Indicated Power Brake Power Mechanical efficiency.
Brake thermal efficiency.
07

What do you mean by priming of a pump. Explain construction and working of single acting reciprocating pump with neat sketch.
07
Q.4

Differentiate between Window and split air conditioners. Draw the figure of Window air conditioner.
07

Define the following terms
Stress ii) Strain iii) Hardness iv) Toughness Factor of Safety vi) Proof resilience vii) Modulus of resilience
07
Q.5

For torsion of a circular shaft, derive the equation Cθ/L with usual notations.
07

Differentiate between ductile and brittle materials. What are significant behaviors of these materials under tensile loading?
07
Q.6

A steel bar 3.5 m long and 2000 mm2 in area hangs vertically, which is securely
fixed on its lower end. If a weight of 10 kN falls on the collar from a height of
8 mm, determine the stress developed in the bar. What will be the strain energy
stored in the bar? Take E as 200 GPa. Explain Linear, shear, lateral, thermal and
volumetric strain.
07
2

Derive relation between Modulus of Elasticity Modulus of Rigidity and Poisson's Ratio
07
Q.7

Draw Shear force and Bending moment diagram for a beam shown in fig. 1.
07

Explain proof of resilience. Write a short note on resilience in case of
Compound stresses.
07
Q.7 Fig. 1