(i) Name the system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse.

(i) The system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse is called sound navigation and ranging or SONAR. Here, ultrasonic waves from a ship are transmitted in all directions. The reflected waves received in the receiver gives the distance and position of the object (e,g, submarine etc.) in water.

(ii) The acoustically measurable quantity related to pitch is frequency and to loudness is intensity of sound.