Question

Two sound waves having intensities 4 unit and 9 unit coming from two coherent sources arrive at a point along the same line simultaneously in same phase .Resultant intensity at the point will be

• A. 13 unit
• B. 25 unit
• C. $\sqrt{97}$ unit
• D. 17 unit

Answer 1

The correct option is B 25 unit

Given,

$I_1=4unit$

$I_2=9unit$

$\theta =0^0$

Resultant intensity,

$I=I_1+I_2+2\sqrt{I_1}\sqrt{I_2}cos\theta$

$I=4+9+2\sqrt{4}\sqrt{9}cos{0}^0$

$I=4+9+12=25unit$