Sound WavesHard
Question
The power of sound from the speaker of a radio is 20MW by turning the knob of the volume control the power of the sound is increased to 400 MW. The power increase in describe as compared to the original power is : -
Options
A.13 dB
B.10 dB
C.20 dB
D.800 dB
Solution
dB = 10log 
= 10 log 
= 10 log20
= 10(1 + 0.3) = 13dB
= 10 log = 10 log20= 10(1 + 0.3) = 13dB
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