A two-fold increase in intensity of a wave implies an increase of (Given: log102 = 0.3010.)
2 dB
10 dB
3.01 dB
0.5 dB
L = 10 log10II0decibel
L' = 10log102II0decibel
L'-L = 10[log102II0-log10II0]
= 10log102 = 10×0.3010 = 3.01 dB