Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test Physics Waves Traveling Sound Waves
The minimum distance between the source of sound and a surface to hear an echo is
1
10 m
2
17 m
3
24 m
4
More than one of the above
5
None of the above