> 00000ME205121902 Pages: 2

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

Third semester B.Tech examinations (S) September 2020

Course Code: ME205
Course Name: THERMODYNAMICS
(Permitted to use Steam tables and Mollier Charts)

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer any three full questions, each carries 10 marks. Marks
1 9) Explain the Zeroth law of thermodynamics. What is its physical significance? (4)
b) What are intensive and extensive properties of a thermodynamic system? (3)
c) What is a thermocouple? What is its engineering application? (3)
2 ஐ Explain the concept of continuum with a suitable example. (4)

b) Describe a few situations in which forms of work other than displacement or (6)
pdv work appear in systems.
3 9) Apply the first law of thermodynamics to a closed system undergoing a change (5)
state and show that energy is a property of the system.
0) If a gas of volume 6000cm? and at a pressure of 100KPa is compressed quasi- (5)
statically according to 7170005081 until volume becomes 2000 cm’, determine
the final pressure and work transfer.
4 a) Obtain the mass balance and energy balance equations for a variable flow (5)
process.
b) Ina Water cooling tower, air enters at a height of 1 m above the ground level (5)
and leaves at a height of 7 m. The inlet and outlet velocities are 20 m/s and 30
m/s respectively. Water enters at a height of 8 m and leaves at a height of 0.8 m.
The velocity of water at entry and exit are 3 m/s and 1 m/s respectively. Water
temperatures are 80°C and 50°C at the entry and exit respectively. Air
temperatures are 30°C and 70°C at the entry and exit respectively. The cooling
tower is well insulated and a fan of 2.25 kW drives the air through the cooler.
Find the amount of air per second required for 1 kg/s of water flow. The values
of C, of air and water are 1.005 and 4.187 kJ/kg K respectively.
PART B
Answer any three full questions, each carries 10 marks.
5 9) Explain at least three different causes of irreversibility associated with a (6)

process.
b) State and prove Carnot’s theorem. (4)

6 a) An ice-making plant produces ice at atmospheric pressure and at 00 from (4)

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