This book is very much in line with our own set of convictions as student requirements at the last hour just before crucial examinations, the time constraints and your quest for authentic and reliable literature-backed answers. It is not the lack of literature but its overwhelming abundance that makes the search for that one precise piece of explanation a tedious job. At the same time, the memory-based synthesis of several questions by students allows a lot of distortion of options and creates confusion among aspirants. This has become a common phenomenon and has made students work unnecessarily longer to master even simple concepts. This book has been written to overcome this lacuna, to address controversial questions, allay fears at the hour of need and boost your confidence.