Question

Four sources of sound each of sound level `10 dB` are sounded together in phase , the resultant intensity level will be `(log _(10) 2 = 0.3)`
A. `40 dB`
B. `26 dB`
C. `22 dB`
D. `13 dB`

Answer 1

Correct Answer - C
Resulant ampulitude will become `4` times.
Therefore , resultant intensity is `16` times
`L_(2) - L_(1) = log_(10) (I_(2))/(I_(1))`
or `I_(2) - 10 = 10 log _(10) (16)`
or `L_(2) = 22 dB`