1. (c) The speed of sound is more in solids, less in liquids and least in gases. Therefore, sound travel fastest in steel medium. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    (c) The speed of sound is more in solids, less in liquids and least in gases. Therefore, sound travel fastest in steel medium.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    See less
    • 4
  2. (a) does not change. On a levelled road h and hence potential energy Ep = mgh remains unchanged. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    (a) does not change. On a levelled road h and hence potential energy Ep = mgh remains unchanged.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    See less
    • 6
  3. (c) A mutual sound has three characteristics namely (i) loudness, (ii) pitch and (iii) quality or timbre. Wavelength is not a characteristic of a musical sound. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    (c) A mutual sound has three characteristics namely (i) loudness, (ii) pitch and (iii) quality or timbre. Wavelength is not a characteristic of a musical sound.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    See less
    • 5
  4. (b) The pitch of sound of a musical note depends upon its frequency only. Higher the frequency, higher the pitch (shrillness) of sound. https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    (b) The pitch of sound of a musical note depends upon its frequency only. Higher the frequency, higher the pitch (shrillness) of sound.

    https://www.tiwariacademy.com/ncert-solutions/class-9/science/chapter-11/

    See less
    • 10