Himachal Pradesh University (HPU) 2007 B.Tech Basic Mechanical Engg. - Question Paper

Basic Mechanical Engg.
Paper-ME-1003
5631

Time Allowed : three Hours Maximum Marks :100
The candidates shall limit their answers precisely within the answer-book (40 pages) issued to them and no supplementary continuation sheet will be issued.
Note : Attempt 5 ques. in all, selecting 1 ques. from every of the parts A,B,C, and D and all the subparts of part E. use of non- programmable calculator is allowed. presume suitable missing data, if any.


part -A
I. 0.9Kg of gas at one bar and 15°C is compressed isentropicaliy to four bar. The quantity modifications from 0.75 m3 to 0.28- m3. obtain the value of gas constant and specific heat at constant pressure. Also obtain change in internal energy. (20)

II. Air compressor takes in air at one bar and 20°C and discharges into a line of inside diameter 10 mm at pressure three bar with velocity 7.7 ms1 The compression is isentropic, compute the work input assuming the inlet velocity to be very small.


part - B
III. State the Kelvin - Planck and Clausius statements of the 2nd legal regulations of thermodynamics and prove their equivalence. (20)

IV. A reversible heat engine is supplied 900 K J of heat from a heat source at 50QK. Tjie engine develops SOOKd Of
net work and rejects heat to 2 heat sinks at 400K and 300K. Determine the engine thermal efficiency and magnitude of heat interaction with every of the sink. (20)


part - C
V. A metallic bar of 50 mm diameter is subjected to a tensile
load of 100 kN. The extension over its 300 mm length
was obtained to be 0.08 mm and change of its diameter
was 0.0035 mm. Determine the modulus of rigidity of
the bar material.

VI. A simply supported beam is loaded. Draw the shear force and bending moment diagrams and determine the maximum bending moment along with its location.


part -D
VII. A beam is of square part of side 'a'. if the maximum allowable bending stress is V, obtain the moment of resistance when the beam part is placed such that
i) 2 sides are horizontal
ii) 1 diagonal is vertical (20)

VIII. 2 shafts of the identical material and identical length, one
solid and the other hollow are to be designed for
transmission of torque. The ratio of diameters in case
of hollow shaft is to be 0.75. If the 2 shafts have to '
carry the identical maximum stress, compute the saving in
weight in case of hollow shaft. (20)


part - E
IX.
a) describe enthalpy. How is it related to. internal energy?
b) State the limitations of 1st legal regulations of thermodynamics.
c) Explain what you understand by the term 'free expansion'.
d) What is the difference ranging from adiabatic process and isentropic process?
e) State the 3rd legal regulations of thermodynamics.
f) Define coefficient of performance.
g) State the difference ranging from heat engine and heat pump.
h) describe internal energy. Is it a state function or process function?
i) describe an isolated system.
j) What is perpetual motion machine of 2nd order? Why such a machine cannot be made in true practice?
k) What is Poisson's ratio? What is its value range i for common engineering materials? .
l) describe 'Elastic Limit* and 'Young's modulus'.
m) discuss briefly the difference ranging from stress - strain curves of mild steel and aluminum.
n) describe thermal stress. State the expression for thermal stress in a bar whose ends are fixed rigidly.
o) describe 'shear force' and 'bending moment' in beams.
P) Based on the kind of supports, name various kinds of beams.
q) describe 'Section modulus'^nd 'moment of resistance of assertion.'
r) Differentiate ranging from a beam and a shaft.
S) State the assumptions made in deriving torsion formula for a shaft of circular part.
t) discuss what you understand from the term 'torsional rigidity'. (20x1=20)


Regards
Get An Unfair Advantage!

Earning:   Approval pending.