JEE Mains · Physics · STD 11 - 14. waves and sound
A small speaker delivers \(2\, W\) of audio output. At what distance from the speaker will one detect \(120\, dB\) intensity sound ... \(cm\) ? [Given reference intensity of sound as \(10^{-12}\,W/m^2\)]
- A \(30\)
- B \(10\)
- C \(40\)
- D \(20\)
Answer & Solution
Correct Answer
(C) \(40\)
Step-by-step Solution
Detailed explanation
Loudness of sound is given by \(\mathrm{dB}=10 \log \frac{I}{\mathrm{I}_{0}}\) (\(I\) is intensity of sound, \(I_0\) is reference intensity of sound) \(120=10 \log \left(\frac{I}{I_{0}}\right)\) \(\Rightarrow I=1 \mathrm{W} / \mathrm{m}^{2}\) Also,…
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