Which of the following statements is incorrect?
Three statements regarding the propagation of sound waves.
I Sound waves propagate through a series of crests and troughs.
II Sound waves require a material medium for their propagation.
III The propagation of sound waves is attributed to the motion of particles.
Among the given statements,
Fill in the blanks.
(1) Sound waves need …………….. medium for propagation.
(2) Technique of echocardiography is based on reflecting property of …………….. waves.
(3) Sound produced by vibration of simple pendulum is …………….. sound.
(4) For determination of the depth of the sea …………….. technique is used.
(5) Pitch of a sound depends upon ………………. of wave.