The Book has been written and presented in a very simple language and in a lucid style so that students can easily the meaning of the theoretical as well as practical problems. A number of solved problems have been given in each chapter. At the end of each chapter there are four parts: Multiple choice questions (MCQ), Short answer type questions, Long answer type questions and a number of unsolved problems with answer type in mind the question pattern of WBTU. At the end of this book three solved question paper had been inserted so that students can get an idea about the question pattern of WBUT.