P08ME35 Basic Thermodynamics B.E Model Question Paper : pescemandya.org

Name of the College : P.E.S College of Engineering
University : Visvesvaraya Technological University
Department : Mechanical Engineering
Subject Code/Name : P08ME35/Basic Thermodynamics
Degree : B.E
Sem : III
Website : pescemandya.org
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/pescemandya.org/4691-mech_question_paper.pdf

Basic Thermodynamics Question Paper

Third Semester B.E. Degree examination, October 2009-10
BASIC THRMODYNAMICS
Time: 3 hrs Max.
Marks: 100

Related : P.E.S College Engineering Chemistry B.E Model Question Paper : www.pdfquestion.in/4696.html

Instructions:
1. Answer any FIVE full questions, choosing at least two from part A and two from part B
2. Use of thermodynamics data hand book permitted

Model Questions

Part-A

1. a. Distinguish between the following with example
i). Open and Closed system
ii). Extensive and Intensive property
iii). Path function and Point function
iv). Macroscopic and Microscopic point of view (06)
b. State and explain Zeroth law of thermodynamics (06)
c. The Mercury column of mercury in glass thermometer reads 75mm & 525mm when the thermometer is at ice point and steam point respectively. The temperature‘t’ varies linearly with ‘x’. Now assume that the length of the mercury column ‘x’ and temperature‘t*’ are related as t* = ax2 + b. Evaluate the temperature on this scale when the temperature is 100oF on the Fahrenheit scale. (08)

2. a. Obtain an expression for displacement work (06) b. Explain the comparison between heat transfer & work transfer and show that work is a path function (06)
c. A spherical balloon having a radius of 30cm contains air at a pressure of 1.5 bar. The radius increases to 40 cm due to heating and during the process the pressure is inversely proportional to diameter. Calculate the magnitude and direction of work (08)

3. a. State precisely the First law of thermodynamics for a closed system undergoing a process & hence prove that Internal energy is a property of the system (10)
b. A centrifugal pump delivers 60 kg of water per second. The inlet and outlet pressure are 10 kPa and 400 kPa respectively. The suction is 2 m below and delivery is 8 m above the centre line of the pump. The suction and delivery pipe diameter are 20 cm and 10 cm respectively. Determine the capacity of the electric motor to run the pump. (10)

4. a. Sketch and explain P-V & P-T diagram for pure substances. (06)
b. Sketch and explain Separating & Throttling calorimeter. (06)
c. The pressure cooker contains 1.75 kg of steam at a pressure of 500 kPa and 0.89 dry. Determine the quantity of heat which must be rejected so that the quantity of steam becomes 0.55dry. (08)

Part-B

5. a. Define Reversible & irreversible process & mention the factors whit render a process irreversible (06)
b. Show that (COP) HP = 1+ (COP) Ref (06)
c. A Carnot engine operates between the temperature of 250oC and 40oC. Its efficiency will be improved with an increase of the source temperature to 300oC holding the rise in temperature at 40oC. Determine the sink temperature reduction necessary to effect the same improvement in efficiency holding the source temperature at 250oC. (08)

6. a. State and prove the Clausius inequality and show that entropy is a property of the system. (10)
b. 300 kJ/hr of heat is supplied at a constant fixed temperature of 270 oC to a heat engine. The heat rejection takes place at 8.5 oC. The following results were obtained. i. 215 kJ/hr are rejected. ii. 150 kJ/hr are rejected. iii. 75 kJ/hr are rejected. Identify which of the results is reversible, irreversible or impossible. (10)

7. a. Define available energy & unavailable energy. (06)
b. Write a short note on Helmoltz & Gibb’s function. (06)
c. 5kg of air at 555 K & 4 bar is enclosed in a system. Determine the availability of system, if the surrounding temperature & pressure is 290 K & 1 bar respectively. If the air is cooled at constant pressure to atmospheric temperature determine the availability & effectiveness. (08)

8. a. State and explain Dalton’s law of partial pressure. (06)
b. State and explain Amagat’s law of partial volume. (06)
c. 2 kg of air undergoes a polytropic process from 330 K and 0.15 m3 to 550 K and 0.02 m3. determine
i) work transfer,
ii) heat transfer,
iii) change in enthalpy and
iv) change in entropy. (08)