# Propagation of Sound Waves Exe-8B Long Ans Concise Physics ICSE Class 9

Propagation of Sound Waves Exe-8B Long Ans Concise Physics ICSE Class 9 Selina Publishers Solutions. There is the solutions of Long Answer type Questions of your latest textbook which is applicable in 2024-25 academic sessionVisit official Website CISCE for detail information about ICSE Board Class-9 Physics.

## Propagation of Sound Waves Exe-8B Long Ans Concise Physics ICSE Class 9 Selina Publishers Solutions

 Board ICSE Class 9 Subject Physics Writer / Publication Concise selina Publishers Chapter-8 Propagation of Sound Waves Exe-8B Infrasonic, Sonic and Ultrasonic Frequency Topics Solution of Exe-8B Long Answer Type Academic Session 2024-2025

### Infrasonic, Sonic and Ultrasonic Frequency

Propagation of Sound Waves Exe-8B Long Ans Concise Physics ICSE Class 9 Selina Publishers Solutions

##### Question-1: Differentiate between infrasonic, sonic, ultrasonic and supersonic sounds.

Answer- Infrasonic sounds: The sounds of frequency less than 20Hz are called infrasonic sounds. The infrasonic sounds have frequency below the lower limit of human hearing.

Example: Sound produced by earthquakes, thunder, volcanoes are in the Infrasonic range. The human Ear cant hear this sound but elephants and whales can hear this.

Ultrasonic sounds: The sound of frequency more than 20,000Hz are called ultrasonics. Ultrasonic sounds have a frequency above the upper limit of human hearing.

Example: The audible range of dogs, cats, moths and mice extends into ultrasound frequencies. They can hear very high frequencies that humans cannot.

##### Question-2: Explain how do bats locate the obstacles and prey in their way.

Answer- Bats locate the obstacles and prey in their path by using ultrasound. They emit an ultrasound which returns after striking an obstacle in their way. By hearing the reflected sound and from the time interval (when they produce ultrasound and when they receive them back), they can judge the direction and the distance of the obstacle in their way.

—: end of Propagation of Sound Waves Exe-8B Long Ans Concise Physics ICSE Class 9 Selina Publishers Solutions : —