Waves and Sound Quiz

Grade 10 · Science · Quiz

Test your knowledge of wave properties, sound behavior, and the physics of how we hear.

Questions

1. Which type of wave is a sound wave?

   1. Transverse mechanical
   2. Longitudinal electromagnetic
   3. Transverse electromagnetic
   4. Longitudinal mechanical
   Show answer

   Answer: Longitudinal mechanical

   Sound requires a medium (mechanical) and its particles vibrate parallel to the direction of wave travel (longitudinal).

2. Increasing the amplitude of a sound wave increases its pitch.

   Show answer

   Answer: False

   Amplitude determines loudness, not pitch. Pitch is determined by frequency — higher frequency = higher pitch.

3. A wave has a wavelength of 2 m and a frequency of 50 Hz. What is its speed?

   1. 25 m/s
   2. 52 m/s
   3. 100 m/s
   4. 48 m/s
   Show answer

   Answer: 100 m/s

   v = fλ = 50 Hz × 2 m = 100 m/s.

4. The maximum displacement of a wave particle from its rest position is the ___.

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   Answer: amplitude

   Amplitude is the measure of a wave's 'height' — the maximum displacement from the equilibrium position. It relates to wave energy and perceived loudness for sound.

5. In which medium does sound travel fastest?

   1. Air
   2. Water
   3. Steel
   4. Vacuum
   Show answer

   Answer: Steel

   Sound travels at ~5,960 m/s in steel because the particles are very close together and can transfer vibrations quickly. Speed of sound increases with density of the medium.

6. The Doppler effect applies to light waves as well as sound waves.

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   Answer: True

   The Doppler effect applies to all waves. For light, it causes redshift (source moving away) and blueshift (source approaching), used by astronomers to measure galaxy movement.

7. The wave equation states that wave speed equals frequency multiplied by ___.

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   Answer: wavelength

   The wave equation v = fλ relates speed (v), frequency (f), and wavelength (λ). Rearranging: λ = v/f.

8. What is the term for the region of a sound wave where air particles are spread apart?

   1. Crest
   2. Trough
   3. Compression
   4. Rarefaction
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   Answer: Rarefaction

   Rarefaction is the low-pressure, low-density region of a longitudinal wave where particles are spread apart. Compression is the high-pressure region.

9. Resonance occurs when an object is driven at a frequency different from its natural frequency.

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   Answer: False

   Resonance occurs when an external force drives an object at its natural frequency, causing the amplitude of vibration to grow dramatically.

10. A dog can hear frequencies up to 65,000 Hz while humans max out at about 20,000 Hz. What term describes these very high-frequency sounds?

    1. Infrasound
    2. Subsonic
    3. Ultrasonic
    4. Resonant
    Show answer

    Answer: Ultrasonic

    Ultrasonic (or ultrasound) refers to frequencies above the human hearing range (>20,000 Hz). Infrasound is below 20 Hz.

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