Sumit Prasad Sah, B.Sc., M.Sc. (Microbiology), is a passionate educator and author with over 8 years of teaching experience in science, especially at the secondary level. He completed his postgraduate education from the University of North Bengal, equipping him with a strong academic and research foundation. He has authored this MCQ-based book for Class 9 Science to help students evaluate and sharpen their understanding through a topic-wise approach. The book includes difficulty-level indicators, concept-based questions, diagram-based problems, and final answer keys—making it an essential resource for effective revision and exam readiness. He also runs a dedicated educational YouTube channel [@thelearners2416], where students can access detailed, NCERT-aligned video explanations on various science topics. His digital content supports visual learning and extends his teaching beyond the classroom. Sumit Prasad Sah continues to inspire learners with the goal of making science simpler, engaging, and accessible for all.