# Propagation Of Sound Waves Exe-8B Short Ans Concise Physics ICSE Class 9

Propagation Of Sound Waves Exe-8B Short Ans Concise Physics ICSE Class 9 Selina Publishers. There is the solutions of  Short 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 Short 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 Frquency Topics Solution of Exe-8B Very Short Answer Academic Session 2024-2025

### Infrasonic , Sonic and Ultrasonic Frquency

Propagation Of Sound Waves Exe-8B Concise Physics ICSE Class 9 Selina Publishers.

##### Question-1:  Can you hear the sound produced due to vibrations of a seconds’ pendulum ? Give reason.

Answer- No, we cannot hear the sound produced due to vibrations of a seconds pendulum because the frequency of the sound produced due to vibrations of a seconds pendulum is 0.5 Hz which is infrasonic and humans can hear sound in sonic range (frequency range 20 Hz to 20K Hz).

##### Question-2: State two properties of ultrasound that make it useful to us.

(i) High energy content, (ii) high directivity.

Answer- The ultrasound waves have a shorter wavelength and thus don’t spread out as rapidly. For this reason, the resulting directivity of the ultrasound devices is far higher than physically possible with any loudspeaker system.

High power ultrasound carry large energy which can break up stony deposits or tissue, accelerate the effect of drugs in a targeted area, assist in the measurement of the elastic properties of tissue, and can be used to sort cells or small particles for research.

Hence, high directivity and high power make ultrasound to be very useful.