Question

Assertion :Sound level increases linearly with intensity of sound. Reason: If intensity of sound is doubled sound level increases approximately 3 dB.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct
  

Answer 1

The correct option is D Assertion is incorrect but Reason is correct

Sound level increases as logarithmic scale of intensity.

Assertion is incorrect

If the intensity of sound is doubled the new sound level will be $10\log \frac{2I}{I_{\circ }}=10\log 2+10\log \frac{I}{I_{\circ }}$ $=3+\log \frac{I}{I_{\circ }}$

Hence sound level increases approximately 3 dB, when intensity is doubled.

reason is correct.