Sound Waves concepts

• Sound waves and related concepts are examined in the document

Sound Wave Characteristics

• The region in a sound wave with higher pressure and density is called compression
• When objects vibrate in the air, sound waves are produced
• A sound level greater than 80 decibels can be harmful
• In a sound wave with 20,000 compressions and rarefactions per second, the frequency is 10,000 Hz
• A mosquito's sound has the highest frequency among the listed animals
• Compression means increased pressure

Tuning Forks

• Tuning forks produce sound through the vibration of metal arms.

Fill-in-the-Blanks

• The region in a sound wave with higher pressure and density is called compression
• Sound generation and propagation require a material medium
• With 1000 compressions/rarefactions per second, the sound wave frequency is 500 Hz
• Different sound notes have different frequencies
• In a loudspeaker, electrical energy is converted into sound energy

Matching (Groups A and B)

• Human larynx matches with vibrations in vocal cords
• Loudspeaker matches with vibrations of screen
• Jaltarang matches with vibrations in air column
• Tuning fork matches with vibration of metal arms
• Sitar matches with vibrations in strings
• Compression matches with increased pressure
• Rarefaction matches with reduced pressure
• Oscillation matches with rarefaction and compression
• Decibel matches with sound level
• Propagation of sound matches with motion of air molecules due to sound

True or False Statements

• False: Vocal cords are approximately 20 mm in length in male, not 15 mm
• True: Vocal cords are approximately 15 mm in length in female
• False: Higher pressure and high density is called compression, not rarefaction
• True: Compression and rarefaction series means sound waves
• True: A hard bump felt while swallowing food is the larynx

Short Answer Definitions

• High-density and pressure regions where particles of a medium are crowded together are called compressions
• Low-density and pressure regions where particles of a medium are spread apart are called rarefactions

Long Answer Questions

• Diagram of a bell jar experiment showing how a vacuum pump affects an electric bell's sound
• Includes labels for the bell jar, electric bell, vacuum pump, increased pressure (compression), reduced pressure (rarefaction), atmospheric pressure, oscillation, vibrating air molecules, and sound propagation
• The movement of air molecules to produce sound

How Musical Instruments Generate Sound

• String-based instruments like guitars change the frequency of vibration by changing the tension or vibrating length of the string
• This results in the generation of different notes
• Instruments like flutes use holes that are opened or closed to change the length of the vibrating air column, creating different notes

The Human Larynx

• Sound is produced in the human larynx, located at the upper end of the windpipe
• Two vocal cords are stretched across the voice box, with a narrow slit between them
• When air from the lungs passes through the slit, the vocal cords vibrate, producing sound
• Muscles control the tension of the vocal cords, making them tight or loose
• The quality of voice changes based on the tightness or looseness of the vocal cords