Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test Physics Waves Supersonic Speeds, Shock Waves
Frequency of ultrasound is
1
> 20,000 Hz
2
> 20 Hz and < 20,000 Hz
3
< 20 Hz and > 20,000 Hz
4
More than one of the above
5
None of the above