InterviewSolution
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InterviewSolution
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The faintest sound the human ear can detect at a frequency of ` kHz` (for which ear is most sensitive) corresponds to an intensity of about `10^(-12)w//m^(2)`. Assuming the density of air `cong1.5kg//m^(3)` and velocity of sound in air `cong300m//s`, the pressure amplitude and displacement amplitude of the sound will be rspectively ____`N//m^(2)` and ____`m`.A. `3xx10^(-5)Pa, (1)/(3pi)xx10^(-10)m`B. `2xx10^(-5)Pa, (2)/(3pi)xx10^(-10)m`C. `5xx10^(-5)Pa, (1)/(pi)xx10^(-10)m`D. `5xx10^(-5)Pa, (4)/(3pi)xx10^(-10)m` |
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Answer» Correct Answer - A `I=(P_m^2)/(2rhoV)` `10^(-12)=(P_m^2)/(2(1.5)(300))` `P_m=3xx10^(-5)Pa` `P_m=BAK=(rhoV^2) A (2pi)/(v//f)` `P_m=(2pirhoVf)A` `3xx10^-5=(2pi)(1.5)(300)(10^3)A` `A=1/3pixx10^(-10)m` |
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