InterviewSolution
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InterviewSolution
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A string with a frequency `n` and `B` string with a frequency `1//8` that of `A`. If the energy remains the same and the amplitude of `A` is `a`, then amplitude of `B` will beA. `2a`B. `8a`C. `4a`D. `a` |
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Answer» Correct Answer - B The energy of a wave travelling with velocity `v` is given by `E= 1/2 mv^(2)` Also `v= amplit udexxangu lar ve locity` `implies v= a omega` `:. E= 1/2ma^(2)omega^(2)` Also `omega= 2pin` Where `n` is frequency. `:. E= 1/2 ma^(2)(2pin)^(2)` `implies E prop a^(2)n^(2)` It is given that energy remains the same. Hence, `E_(A)=E_(B)` `:. (a_(A)/(a_(B)))^(2)=(n_(B)/(n_(A)))^(2)` Given,`n_(A)=n,n_(B)=n/8` `:. (a_(A))/(a_(B))=(n//8)/(n)=1/8` `implies a_(B)=8a_(A)= 8a` |
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