Prof. M.T. Dharmadhikari got his PG degree in Physics in first class in 1965 from RTM, Nagpur University and immediately joined a reputed local college as lecturer. He taught nearly all branches of Physics to the different degree classes for a long period for 38 years and retired in 2003 after superannuation. He was known as an excellent teacher in Physics in the student-world. For last 10 years of his service, he worked as Head of Department of Physics in the same institute.       He joined FIP programme and COSIP programme of UGC from 1978 to 1983 and got rice experience of research.       He also was elected for two terms on Board of Studies of the university and helped modernize the syllabus of degree and PG classes in Physics.     He joined a group of enthusiastic and devoted teachers. The group was involved in coaching students for various competitive examinations like NTSE, IIJ-JE, SEEE, AIEEE, central CBSE PMT for long period.     He has attended many workshops in Physics, National and International Seminars held by different universities and Maharashtra Government.     He has authored many books on Physics for +2 levels and also for degree classes. These books were very well received by students and teachers.     He has used his long teaching and research experience and put in very much hard work in writing this book and is sure that book will serve an efficient guide to the students appearing for various competitive examinations.       He wishes bright success and very good health to all students and teachers.