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NCERT Questions
Last updated at April 16, 2024 by Teachoo
NCERT Question 7 A person has a hearing range from 20 Hz to 20 kHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m sā1. Hearing range for humans = 20 Hz to 20 kHz = 20 Hz to 20,000 Hz Speed to sound = v = 344 m/s We know that, Speed of sound = Wavelength Ć Frequency Wavelength = (ššššš šš š šš¢šš)/š¹šššš¢šššš¦ Frequency = 20 Hz Wavelength = (ššššš šš š šš¢šš)/š¹šššš¢šššš¦ = 344/20 = 172/10 = 17.2 m Frequency = 20,000 Hz Wavelength = (ššššš šš š šš¢šš)/š¹šššš¢šššš¦ = 344/20000 = 172/10000 = 0.0172 m Wavelength of frequency 20 Hz is 17.2 m Wavelength of frequency 20000 Hz is 0.0172 m