Exam-style question
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If a sound increases from 20 dB to 40 dB, how many times more intense is the sound?.
- A.2 times
- B.4 times
- C.10 times
- D.100 times
Model answer
What a good answer should say
- 100 times
Explanation
Why this works
The decibel scale is logarithmic. An increase of 10 dB represents a tenfold increase in intensity.
Therefore, a change from 20 dB to 40 dB (20 dB increase) means the intensity increases by 10^2 = 100 times.
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