I am thankful to the teaching and student community for the overwhelming response for the second edition. I was receiving constant feed back from students and teachers. One of the requests was to add objective type questions, which I have included in all the chapters in this edition. This, I hope will help the students in testing their comprehension. The figures and text in all chapters have been thoroughly reviewed and the additions and deletions wherever necessary have been carried out in various chapters.

I am thankful to Prof. S. Sampath of Sri Venkateswara College of Engineering, Sriperumbudur, Chennai and Prof. A. Ramesh of Indian Institute of Technology Madras, who helped me in reviewing chapters and objective type questions.

This edition would not have been brought to this perfection but for the dedicated effort of Ms.Vijayashree, who is responsible right from the beginning in bringing out all the three editions. I am grateful to her for all the support in the preparation of the camera-ready copy.

I hope this edition will also receive the overwhelming support from the academia and practicing engineers. I will be thankful for any constructive criticism for improvements in future editions.

V GANESAN