The speed of ultrasound in air is :

1. the same as audible sound
2. less than audible sound
3. more than audible sound
4. equal to the speed of light

Echo-cardiography is used to obtain the image of

1. lungs
2. liver
3. heart
4. kidney

…………… can hear the highest frequency range of sound.

1. Whales
2. Dogs
3. Cats
4. Bats

Choose the correct statement :

1. Ultrasonic waves travel faster than supersonic waves.
2. Sonic waves travel faster than supersonic waves.
3. Sonic waves travel faster than ultrasonic waves.
4. Sonic and ultrasonic waves travel with the same speed.