RAJADHANI POLYTECHNIC COLLEGE
Fourth Semester Diploma Revision Test
Applied Thermodynamics
Maximum marks :30 Time :1 Hour
PART A
(Answer any three question in one or two sentences. Each Question carries 2 marks)
1. What do you understand by a thermodynamic process.
2. Define available energy.
3. What is meant by theoretic thermal efficiency.
4. Define Polytropic Process
5. State Stefan-Boltzmann’s Law, Fourier law of heat Conduction, Newton Law of
Cooling
PART B
(Answer any two of the following questions. Each question carries 5 marks)
1. Define Absorptivity, Transmittivity and Emissivity
2. Derive an Expression for heat transfer through composite wall
3. Derive Expressions for Efficiency of Otto Cycle
4. Derive p-V-T Relationship, Change in Internal Energy, Work done and Heat Transfer
of an Isothermal Process
PART C
(Answer any two of the following questions. Each question carries 7 marks)
1. Calculate the air standard efficiency of an engine working on Otto cycle, if the
pressure at the beginning and end of the compression are 1 bar and 7 bar respectively.
Take the index of compression as 1.4
2. A gas engine working on 4 stroke constant volume cycle gave the following results
during a test of an hour’s duration.
Heat supplied by the fuel = 10280 kJ/min, indicated power = 20.8 kW, brake power =
18.4 kW, mass of cooling water circulated = 660 kg/h, cooling water temperature rise
= 34.20C. Heat loss to exhaust gas = 8%. Prepare a heat balance sheet for the engine.
3. A furnace wall is built with 200mm thick refractory bricks and 150 mm insulating
bricks. The temperature of the surrounding is 400C whereas that inside the furnace is
10000 C. The thermal conductivities of the refractory bricks and insulating bricks are
5 W/mk and 0.5 W/mk respectively. Determine the heat loss per square meter per
minute.
Fourth Semester Diploma Revision Test
Applied Thermodynamics
Maximum marks :30 Time :1 Hour
PART A
(Answer any three question in one or two sentences. Each Question carries 2 marks)
1. What do you understand by a thermodynamic process.
2. Define available energy.
3. What is meant by theoretic thermal efficiency.
4. Define Polytropic Process
5. State Stefan-Boltzmann’s Law, Fourier law of heat Conduction, Newton Law of
Cooling
PART B
(Answer any two of the following questions. Each question carries 5 marks)
1. Define Absorptivity, Transmittivity and Emissivity
2. Derive an Expression for heat transfer through composite wall
3. Derive Expressions for Efficiency of Otto Cycle
4. Derive p-V-T Relationship, Change in Internal Energy, Work done and Heat Transfer
of an Isothermal Process
PART C
(Answer any two of the following questions. Each question carries 7 marks)
1. Calculate the air standard efficiency of an engine working on Otto cycle, if the
pressure at the beginning and end of the compression are 1 bar and 7 bar respectively.
Take the index of compression as 1.4
2. A gas engine working on 4 stroke constant volume cycle gave the following results
during a test of an hour’s duration.
Heat supplied by the fuel = 10280 kJ/min, indicated power = 20.8 kW, brake power =
18.4 kW, mass of cooling water circulated = 660 kg/h, cooling water temperature rise
= 34.20C. Heat loss to exhaust gas = 8%. Prepare a heat balance sheet for the engine.
3. A furnace wall is built with 200mm thick refractory bricks and 150 mm insulating
bricks. The temperature of the surrounding is 400C whereas that inside the furnace is
10000 C. The thermal conductivities of the refractory bricks and insulating bricks are
5 W/mk and 0.5 W/mk respectively. Determine the heat loss per square meter per
minute.
