JNTU B.Tech II THERMAL SCIENCE Previous Question Paper (May/June - 2019 - R16)

Differentiate between microscopic and macroscopic thermodynamics.

What is the importance of thermodynamic equilibrium? Explain.

Explain any one of the Joule’s experiment for the first law of TD.

How to understand the quality of temperature and discuss.

State and explain the Claussius statement and discuss its application.

Explain the principle of entropy increase based on second law of TD.

Draw the actual cycle for the petrol engine and explain.

Define the term mean effective pressure and discuss the importance.

Explain the significance of valve timing diagram in four stroke engine.

Differentiate between the functions of carburetor and fuel injector.

What are the major differences between reversible and irreversible processes? Explain the method to estimate the work transfer and heat transfer for the irreversible process.

To a closed system, 150 kJ of work is supplied. The initial volume is 0.6 m³ and pressure of the system changes as p = 8- 4V, where p is in bar and V in m³. Determine the final volume and pressure of the system. Comment on the results.

Show that the heat transfer and work transfer are not point functions and are depending on path followed.

A mass of 2.5 kg of air is compressed in a quasi static process from the initial pressure of 0.1 MPa to a final pressure of 0.7 MPa for which PV = constant. The initial specific volume is 0.80 m³/kg. Find the work done by the piston to compress the air.

State and explain Zeroth law of thermodynamics and discuss the significance of the temperature scale.

Draw the constant volume gas thermometer and explain the working principle along with the property of thermometry.

Explain different Corollaries of first law of thermodynamics along with the suitable examples.

A turbo compressor delivers 2.33 m³/s of air at 0.276 MPa, 43°C which is heated at this pressure to 430°C and finally expanded in a turbine which delivers 1860 kW. During the expansion, there is a heat transfer of 0.09 MJ/sec to the surroundings. Calculate the turbine exhaust temperature if changes in kinetic and potential energy are negligible. Take Cp = 1.005 kJ/kg-K and R = 0.287 kJ/kg-K for air.

Explain the importance of Claussius inequality for understanding the second law of thermodynamics.

Based on the Carnot principle a reversible heat engine is designed for the maximum efficiency with the temperature limits of 330 K and 900 K. What is the maximum power generated by the engine for the heat supplied to the engine is 1800 kW? And also calculate the heat rejected.

State and explain the third law of thermodynamics and along with the practical applications.

A domestic refrigerator is loaded with food and the door closed. During a certain period the machine consumes 1 kWh of energy and the internal energy of the system drops by 5000 kJ. Find the net heat transfer for the system.

Compare Otto cycle, Diesel cycle and dual cycle for the same compression ratio on the T-s diagram.

A petrol engine has a total swept volume of 2000cm³ and the clearance volume in the cylinder is 60 cm³. If the pressure and temperature at the beginning of the compression are 1.02 bar and 24°C, maximum cycle temperature is 1400°C, Calculate i) air standard efficiency ii) mean effective pressure.

Derive the expressions for efficiency and mean effective pressure of Otto cycle.

In an air standard diesel cycle a compression ratio is 15 and compression begins at a pressure of 0.1 MPa and at a temperature of 40°C. The heat added is 1.675 MJ/kg. Find (i) The max temp of the cycle, (ii) the work done per kg of air, (iii) the cycle efficiency, (iv) the temp at the end of the isentropic expansion, (v) the cut-off ratio, (vi) the max pressure of the cycle, and (vii) the mean effective pressure of the cycle.

Differentiate between four stroke engine and two stroke engine based on the performance and functionality.

What are different modes of fuel admission into the engine cylinder? Explain them in detail.

Explain different methods of lubrication systems used in internal combustion engines with suitable diagrams.

Draw the diagram of magnetic ignition system and explain the salient features of this system.