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Note is a sound

always unpleasant to listenof a single frequencyof mixture of two frequencies onlyof mixture of several frequencies

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A key of a mechanical piano struck gently and then struck again but much harder this time. In the second case

both loudness and pitch will remain unaffectedsound will be louder, but pitch will be lowersound will be louder, and pitch will also be highersound will be louder, but pitch will not be different

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In SONAR, we use

audible sound wavesradio wavesinfrasonic wavesultrasonic waves

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Sound travels in air if

both particles as well as disturbance travel from one place to anotherdisturbance movesthere is no moisture in the atmosphereparticles of medium travel from one place to another

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When we change feeble sound to loud sound, we increase its

wavelengthvelocityamplitudefrequency

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In the following curve half the wavelength is

A ED EB DA B

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Earthquake produces which kind of sound before the main shock wave begins

none of the aboveaudible soundinfrasoundultrasound

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Infrasound can be heard by

human beingsrhinocerosbatdog

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Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is adjusting

loudness of soundfrequency of the sitar string with the frequency of other musical instrumentsamplitude of sound onlyintensity of sound only