The depth of a sea can be determined by using SONAR. Consider the following statements about it :
(1) It uses ultrasonic waves for measurement of depth of a sea.
(2) The speed of ultrasonic waves in sea water is the same as that of sound in air.
(3) Time taken by the ultrasonic waves reflected from the bottom of the sea to reach the detector is used to measure the depth.
Which of the above statement(s) is/are correct ?
(A) (3) only (B) (1) and (3) only (C) (2) and (3) only (D) (1), (2) and (3) only
