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#### A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of Option 1) Option 2) Option 3) Option 4)

As we learnt in

Effect of temperature on speed of sound -

- wherein

T is in Kelvin

So velocity increses with increase in temperature.

$L_{1}= 10\log \left ( \frac{I_{1}}{I_{0}} \right ),L_{2}= 10\log \left ( \frac{I_{2}}{I_{0}} \right )$

$\therefore L_{1}-L_{2}= 10\log \left ( \frac{I_{1}}{I_{0}} \right )-10\log \left ( \frac{I_{2}}{I_{0}} \right )$

$or\: \Delta L= 10\log \left ( \frac{I_{1}}{I_{2}} \right )$

$or \: 20\; dB\: = 10\log \left ( \frac{I_{1}}{I_{2}} \right )$

$or\: 10^{2}= \frac{I_{1}}{I_{2}} or\: \: I_{2}= \frac{I_{1}}{100}$

Correct option is 1.

Option 1)

This is the correct option.

Option 2)

This is an incorrect option.

Option 3)

This is an incorrect option.

Option 4)

This is an incorrect option.