General Science Dhwani Ka Source Wa paravarti Satah Ke Beech Minimum Doori Kitni Honi Chahiye , Jisse Ki Pratidhwani Spashta roop Se Sunayi De Sake ?

ध्वनि का स्त्रोत व परावर्ती सतह के बीच न्यूनतम दूरी कितनी होनी चाहिए , जिससे कि प्रतिध्वनि स्पष्ट रुप से सुनाई दे सके ? - What should be the minimum distance between the source of sound and the reflecting surface so that the echo can be heard clearly? - Dhwani Ka Source Wa paravarti Satah Ke Beech Minimum Doori Kitni Honi Chahiye , Jisse Ki Pratidhwani Spashta roop Se Sunayi De Sake ? General Science in hindi,  Physics 17 Meeter question answers in hindi pdf  24 Meeter questions in hindi, Know About 10 Meeter General Science online test General Science notes in hindi quiz book    30 Meeter