Q1
The pitch of a sound depends on its:
Afrequency
Bamplitude
Cquality
Dspeed only
CBSEClass 9 (CBSE)ScienceCh 11 · Topic 2
Characteristics of Sound
Learning the properties of sound like pitch, loudness, and quality.
Core concept
Frequency is measured in hertz (Hz), representing the number of vibrations per second, and the human ear can typically detect sounds between 20 Hz and 20,000 Hz — sounds below this range (infrasound) or above it (ultrasound) exist but are inaudible to humans, though some animals like dogs and bats can detect frequencies beyond human hearing range. Loudness is measured in decibels (dB), and prolonged exposure to very loud sounds (above about 85 dB) can cause hearing damage.
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• Pitch depends on frequency (higher frequency = higher pitch); loudness depends on amplitude.
• Sound quality (timbre) distinguishes different sources producing the same pitch/loudness.
• Frequency is measured in hertz (Hz); humans hear roughly 20 Hz to 20,000 Hz.
• Loudness is measured in decibels (dB); prolonged exposure above ~85 dB can damage hearing.