For the chapter Dual Nature of Radiation in Physics you can find previous year question papers PYQ for Class 12 and Class 11 which include questions on topics like photoelectric effect wave particle duality de Broglie wavelength and related numerical problems. These PYQs help students understand important concepts commonly asked questions and the exam pattern. A reliable source to download subject wise PYQs including Dual Nature of Radiation is Careers360 which provides PDFs of previous year question papers and answer keys for CBSE State Boards and other board exams. You can access these papers and practice for exams at https://school.careers360.com/boards/cbse/cbse-class-12-physics-previous-year-question-papers