1. What is pitch of a sound? On what does it depend?
Answer: Pitch is the characteristic of sound that tells whether a sound is shrill or deep. It depends on the frequency of the sound.
2. Define loudness of sound. On which factor does it depend?
Answer: Loudness is the characteristic of sound that tells how strong or weak a sound is. It depends on the amplitude of the sound wave.
3. What is the unit of loudness? Is it a physical quantity?
Answer: The unit of loudness is decibel (dB). Loudness is not a physical quantity; it is a sensation.
4. What is meant by quality or timbre of sound?
Answer: Quality or timbre is the characteristic of sound that helps us distinguish between sounds produced by different sources even when they have the same pitch and loudness.
5. Two sounds have the same pitch and loudness but sound different. Which characteristic is responsible for this?
Answer: The difference is due to the quality (timbre) of the sound.
6. How does frequency affect the pitch of a sound?
Answer: Higher the frequency, higher is the pitch of the sound. Lower the frequency, lower is the pitch.
7. State the relation between amplitude and loudness of sound.
Answer: Loudness of a sound increases with increase in amplitude and decreases with decrease in amplitude.
8. Define frequency of a sound wave and write its SI unit.
Answer: Frequency is the number of vibrations produced per second. Its SI unit is hertz (Hz).
9. Why do different musical instruments produce different sounds even when they play the same note?
Answer: Different instruments produce different sounds due to difference in their quality (timbre).
10. Arrange the following sounds in increasing order of pitch: drum, guitar, whistle.
Answer: Drum < Guitar < Whistle