डेसीबल इकाई का प्रयोग किया जाता है ? - What is the decibel unit used for? - Decible Ikai Ka Prayog Kiya Jata Hai ? General Science in hindi, Physics ushma Ki Tivrata Ke Liye question answers in hindi pdf Dhwani Ki Tivrata Ke Liye questions in hindi, Know About Prakash Ki Gati Ke Liye General Science online test General Science notes in hindi quiz book Radion Tarang Ki avriti Ke Liye
Sound