D D3818 Pages: 2

Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, APRIL 2018

Course Code: ME205
Course Name: THERMODYNAMICS (AN, MA, ME, MP)

(Permitted to use Steam tables and Mollier charts)

Max. Marks: 100 Duration: 3 Hours
PART A
Answer any three full questions, each carries 10 marks Marks
1 2) How the Zeroth law of Thermodynamics forms the basis for the measurement of (4)
temperature?

b) How the state function varies from path functions with one example each? (6)

2 93) Draw the isochoric, isobaric, isothermal, adiabatic and polytropic processes in a (6) single
P-v diagram. Give reason for the shape of each process

b) What is a quasi-static process? Is it a reversible process? How? (4)

3 a) How the First Law of Thermodynamics is applied to a process? Show how this (6)
formulation changes when it completes a thermodynamic cycle.

b) 1 kg of air at 4 bar and 150°C is contained in a system. It is expanded by a (4)
reversible process till the pressure falls to 1.01325 bar. The gas is then heated at
constant pressure process until the heat content is increased by 72.5 kJ. Calculate:

i) The work done ii) The pressure and temperature at the end of the constant
pressure process iii) The index of expansion, if the above processes are
replaced by a single reversible polytropic process giving the same work
between the same initial and final states.

Take Cp = 1 kJ/kg K, Cv = 0.714 kJ/kg K.

4 93) Deduce the Steady Flow Energy Equation (SFEE) applied to a steam turbine. (4) 0) 10kg
of air per minute is delivered by a centrifugal air compressor. The inlet and (6)

outlet conditions of air are C; = 12 m/s, [1 = 1 bar, ५1 0.5 m/kg and C2 = 90 m/s,

‎bar, v2= 0.15 m*/kg. The increase in enthalpy of air passing through the‏ 8 = دم

‎compressor is 250 kJ/kg and heat loss to the surroundings is 900 kJ/min. Find

‎i) Motor power required to drive the compressor;
ii) Ratio of inlet to outlet pipe diameter.
Assume that inlet and discharge lines are at 1.5 m height difference.
PART ந
Answer any three full questions, each carries 10 marks
5 a) Compare the COP of heat pump to that of a refrigerator. What is the reason for (4)
their difference. b) Explain the internal and external irreversibility with practical examples.
(6)
6 a) Explain the working of a Carnot cycle using P-v and T-s diagrams. State why a (6)

‎Carnot engine can’t be realised? b) An inventor claims that he developed a refrigerator for removing a
heat of 1440 (4)

‎kJ/min from a temperature of 0°C to 25°C by receiving an external work of 2
kW. Comment on his claim.

‎7 a) Explain the term availability function. For a non-flow process. (4) b) In a power station,water
enters the boiler at saturated condition and leaves as (6)

‎saturated steam the saturated steam at 200°C by receiving heat from hot gases in