1) The range of hearing of a normal human being is a) 20 Hz to 20000 Hz b) below 20 Hz 2) Sound waves with frequency more than 20000 Hz are called a) Audible sound b) Ultrasonic sound 3) Which of the following animals can hear ultrasonic sound a) Humans b) Bats 4) Which device uses ultrasonic waves to see internal organs of the body? a) stethescope b) Ultrasound scanner 5) Ultrasonic waves are used in hospitals mainly for a) hearing test b) Ultrasonography 6) Which sound cannot be heard by the human ear? a) sound of frequency 10000 Hz b) sound of frequency 25000 7) The heart imaging technique is called a) echocardiology b) ultrasonography 8) ultrasonic waves are suitable for detecting cracks inside metal blocks because they a) pass through metals and get reflected from cracks b) get absorbed completely by metals 9) During ultrasonography , images of internal organs are formed because ultrasonic waves a) are absorbed by body tissues b) are reflected differently by tissues of different. densities 10) ultrasonic waves are used to break kidney stones into small pieces. This process helps because a) stones dissolve easily b) small pieces pass out with urinr

Physics

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