Q: A long glass tube is held vertically in water. A tuning fork is truck and held over the tube. Strong resonance are observed at two successive lengths 0.50m and 0.84 m above the surface of water. If the velocity of sound is 340 m/s, then the frequency of the tuning fork is
(a) 128 Hz
(b) 256 Hz
(c) 384 Hz
(d) 500 Hz
Ans: (d)