An auditorium has volume of $10^5 \mathrm{~m}^3$ and surface area of absorption $2 \times 10^4…
An auditorium has volume of $10^5 \mathrm{~m}^3$ and surface area of absorption $2 \times 10^4 \mathrm{~m}^2$. Its average absorption coefficient is 0.2 . The reverberation time of the auditorium in seconds is
$6.5$
$5.5$
$4.25$
$3.25$
Solution
Reverberation time $T=\frac{0.017 v}{a s}$
where, $a=$ average absorption coefficient
$
\begin{aligned}
& =0.2 \\
T & =\frac{0.17 \times 10^5}{0.2 \times 2 \times 10^4}=4.25 \mathrm{sec}
\end{aligned}
$