InterviewSolution
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InterviewSolution
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The adjacent diagram shows three ‘different modes of vibrations P, Q and R of the same string.(i) Which vibration will produce a louder sound and why? (ii) The sound of which string will have maximum shrillness? (iii) State the ratio of wavelengths of P and R. |
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Answer» (i) The loudness or softness of a sound is determined by the amplitude (or intensity) of the wave. In this case the amplitude of R is greater than the amplitude of other vibration modes. Hence, the vibration R will produce more sound than the other two. Louder sound corresponds to the wave of larger amplitude. (ii) Shrillness or Pitch of a note depends on the wavelength or frequency of wave and here the vibration P has m ore frequency than others. If f is the principle frequency, then Frequency (P) = 3f Frequency (Q) = 2f Frequency (R) = f Hence P has more shrillness than others. (iii) If the frequency of vibration of R = f, frequency of vibration of Q = 2f, and that of P =3f. Ratio fP/fR=3/1 fP:fR=3:1 As f∝1/λ hence λP/λR=1:3 |
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