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.
(1) Sound waves need material medium for propagation.
(2) Technique of echocardiography is based on reflecting property of ultrasonic waves.
(3) Sound produced by vibration of simple pendulum is infrasonic sound.
(4) For determination of the depth of the sea SONAR technique is used.
(5) Pitch of a sound depends upon frequency of wave.