PREFACE Dear friends, This book of General Science is being remained very popular among the aspirants of various Competitive Exams by the name of Lucentís General Science which has been published now as KSagars General Science. The book has been prepared/composed on the basis of a comprehensive and rigorous observations of the trends of previous yearsí papers of various competitive exams like UPSC, MPSC, CSAT-IAS, NDA, CDS, State PCS, SSC, Railway etc. in a very lucid, concise and updated manners. According to the recent trends of the competitive exams General Science has become a problematic section of asking the questions because of no prescribed syllabus and an extensive coverage area. This is the reason why the aspirants of Science background also suffer and do mistakes in the science segments during the exams. This book has been compiled on the basis of NCERT books and some other standard references, manual of Science. I have tried to compose this book in such a way that even the desired aspirants of non-science background have no problems in conceptualize the book. This book consists of five segmentsñ (1) Physics, (2) Astronomy and Space Science, (3) Computer and Its Applications, (4) Chemistry and (5) Biology/Life Science.At the end of the contents of every segment important objective questions relevant to the corresponding topic and some previous yearsí questions of the Competitive Exams have been incorporated. Every precautionary measure has been taken to compile the book errorfree, however if any mistake/discrepancy is to be found then I would be regretful. Every valuable suggestion/view/opinion of the readers/academicians/ teachers would be highly appreciated. Author Ravi Bhushan Mobile No. 8002890872 wr.ravibhushan@gmail.com