This document contains 20 physics questions and their answers related to waves, sound, and optics. It is from the Buddha Science & Technical Institute in Ranchi, Jharkhand, India and encourages joining their courses to prepare for IIT-JEE and NEET exams. The questions cover topics like resonance, wave properties, sound waves, Doppler effect, redshift, and more. For each question, the correct multiple choice answer is provided along with an explanation of the concept.