CH 8 PROPAGATION OF SOUND WAVE

USES OF MULTIPLE REFLECTION OF SOUND

USES OF MULTIPLE REFLECTION OF SOUND Megaphones or loudhailers, horns, musical instruments such as trumpets and shehanais, are all designed to send sound in a particular directionwithout spreading it in all directions, In these instruments, a tube followed by a conical opening reflects sound successively to guide most of the sound waves from the source …

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CHARACTERISTICS OF A SOUND WAVE

Characteristics of a sound wave Sound waves have following characteristics:(1) Amplitude(2) wavelength(3) Frequency(4) Time period (5)Velocity Amplitude. The maximum displacement of each particle from its mean position is called amplitude.It is denoted by A.Its SI unit is metre (m). Its CGS unit is Centimeter (cm) Wavelength The distance between two nearest (adjacent) crests or troughs of a wave is called …

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SOUND WAVES ARE LONGITUDINAL WAVES

The regions where the coils become closer are called compressions (C) and the regions where the coils are further apart are calledrarefactions (R). As we already know, sound propagates in the medium as a series of compressions and rarefactions. Now, we can compare the propagation of disturbance in a slinky with the sound propagation in …

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SOUND NEEDS A MEDIUM TO TRAVEL

Sound is a mechanical wave and needs a material medium like air, water, steel etc. for its propagation. It cannot travel throughvacuum, which can be demonstrated by the following experiment. Take an electric bell and an airtight glass bell jar. The electric bell is suspended inside the airtight bell jar. The bell jar is connected …

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Hearing Aid

Hearing Aid: People with hearing loss may need a hearing aid. A hearing aid is an electronic, battery operated device. The hearing aid receives sound through amicrophone. The microphone converts the sound waves to electrical signals. These electrical signals are amplified by an amplifier. The amplified electrical signals are given to a speaker of the …

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H. R. Hertz

Heinrich Rudolph Hertz was born on 22 February 1857 in Hamburg,Germany and educated at the University of Berlin. He confirmed J.C. Maxwell’s electromagnetic theory by his experiments. He laid the foundation for future development of radio, telephone, telegraph and even television. He also discovered the photoelectric effect which was later explained by Albert Einstein. The …

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