The fourth and the final book of the Disha's Textbook series of PHYSICS for IIT-JEE Entrance examination. The book covers Reflection, Refraction, Dispersion, Optical Instruments, Electron, Photon, Atom, Nuclear Physics and Electronics. A revolutionary book with a unique presentation style will definitely help you learn Optics & Modern Physics in a different way. The book has been written with a focus on NEW PATTERN OF IIT-JEE. Each chapter has exhaustive theory, well discussed numerous solved examples, Problem Solving Tips & Techniques, Brilliant Method of Analysis & Techniques and 4 levels of EXERCISES - 3 based on MCQ's (including new pattern) and the 4th exercise based on Subjective Problems (including Numeric Answer Type questions). The book also provides a REVISION CHAPTER, which includes Formulae, Important points and a Revision Exercise. DETAILED SOLUTIONS to the subjective problems are provided at the end of the Books.