This textbook is specifically designed for the students of B.E. / B.Tech., B. Arch., Diploma in Engineering, and those preparing for U.P.S.C. examinations (engineering and civil services), AMIE, GATE, and various other engineering competitive examinations. It is written in simple and lucid language so that students can understand the subject even by self-study. This book is intended to be useful also to the faculty members teaching the subject. It will serve as a valuable source of information and reference book for post-graduate students, interview preparations, and industry professionals alike.