Class 9 Sound Important QuestionsImportant Questions Notes
Sound Important Questions
- What do you mean by the intensity of sound ? What is the S.I. unit of intensity of sound?
- Establish relationship between speed of sound, its wavelength and frequency.
- Write the factors on which the speed of sound depends upon.
- Waves of frequency 100 Hz are produced in a string as shown in figure. Give its : (a) amplitude, (b) wavelength, (c) velocity
- The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?
- Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why ?
- Distinguish between transverse and longitudinal waves.
- What is reverberation? What are methods to reduce reverberation?
- Define echo. Calculate the minimum distance between source and obstacle to hear an echo.
- A stone js dropped into a well 44 m deep and the sound of splash is heard after 3.12 sec. Find the speed of sound in air.
- What is pitch of a sound? Which wave property of sound determines the pitch of the sound? Draw the wave shapes for a low pitched and high pitched sound.
- A particular transmitter of Aakashvani broadcasts at 420.5 m wavelength. Given the speed of radio waves 3 x 108 ms-1. Calculate the frequency at which the radio station broadcasts its programme.
- Given that sound travels in air at 340 m/sec, find the wavelength of the waves in air produced by 20 kHz sound source. If the same source is put in a water tank, what would be the wavelength of the sound waves in water? Speed of sound in water is 1480 m/s.