Why is a medium necessary for sound?

A. sound particles के vibration से travel करती है / Sound travels by vibration of particles

Step 1: Identify the concept: this is sound propagation. Step 2: Sound is a mechanical wave and moves through vibration of particles so it needs a medium. Step 3: Remember sound cannot travel in vacuum.

Step 1: concept पहचानें: यह sound propagation है। Step 2: Sound mechanical wave है और particles के vibration से आगे बढ़ती है इसलिए medium चाहिए। Step 3: Sound cannot travel in vacuum याद रखें।