Question

A sound has an intensity of $3\times {10}^{-8}W/m^2$. What is the sound level in dB (decibels)? (Given,$log3=0.477$)

• A. $4.477dB$
• B. $0.4477dB$
• C. $44.77dB$
• D. None of these

Answer 1

The correct option is C $44.77dB$

The level of sound or loudness may be expressed in decibels above the standard threshold of hearing $I_0$ . The expression is
$B=10lo{g}_{10}\left(I/I_0\right)$

or, $B=10lo{g}_{10}(3\times {10}^{-8}/{10}^{-12})$

or,$B=10\times 4log3=44.77dB$.