Class 9 Science Chapter 11 | All NCERT exercise questions detailed explanation and solutions скачать в хорошем качестве

Class 9 Science Chapter 11 | All NCERT exercise questions detailed explanation and solutions

detailed explanation for all NCERT exercise solutions. questions- • Loudness is a physiological response of the ear to the intensity of sound. • The amount of sound energy passing each second through unit area is called the intensity of sound. • The audible range of hearing for average human beings is in the frequency range of 20 Hz – 20 kHz. • Sound waves with frequencies below the audible range are termed “infrasonic” and those above the audible range are termed “ultrasonic”. • Ultrasound has many medical and industrial applications. Exercises 13. A sound wave travels at a speed of 339 m s–1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible? 14. What is reverberation? How can it be reduced? 15. What is loudness of sound? What factors does it depend on? 16. How is ultrasound used for cleaning? 17. Explain how defects in a metal block can be detected using ultrasound. Some important hashtags- #class9science #physicsclass9 #soundclass9 #ncert #science #cbse2025_26 #echolocation #ultrasound #onestot #physics #educationalvideo