For a sound source of intensity `IW//m^(2)`, corresponding sound level is `B_0` decibel If the intensity is increased to `4I`, new sound level becomes.

Options

A. `2B_(0)dB`
B. `(B_(0) + 3)dB`
C. `(B_(0) + 6)dB`
D. `4B_(0)dB`

Answer

C

Explanation

`B_(o) = 10 log' (l)/(l_(o)) , B_(1) = 10 log '(4l)/(l_(o)) , = 10 log 4 + 10 "log"(l)/(l_(o))`
`= 20 log 2 + B_(o) , = B_(o) + 6`
Hence when intensity is increased four times, level becomes `(B_(0) + 6)` decibels