Question

The intensity of sound during the festival season increased by $100$ times. This could imply a decibel level rise from

• A. $20$ to $120dB$
• B. $70$ to $72dB$
• C. $100$ to $10000dB$
• D. $80$ to $100dB$

Answer 1

The correct option is D $80$ to $100dB$

$L_2-L_1=10{\log }_{10}\left(\frac{I}{I_0}\right)$,
$I=100I_0$
so
$10\times \log \frac{100I_0}{I_0}$
$L_2-L_1=20$
So level rises by $20dB$

Hence from given option, D would be correct option.