Question
QUES TWO IDENTICAL SOUNDS s1 &s2 reach at a point P in phase. resultant loudness at a point P is ndB higher than loudness of s1 the value of n =?
ANS) 6
Joshi sir comment
Let intensity of one source = I
then intensity at a point where two waves meet in phase = I+I+2√I√Icos0 = 4I
now loudness = 10logI/I0 due to a single source
and loudness at the point where 2 waves meet in phase = 10log4I/I0 = 10logI/I0+ 10log4
since 10log4 = 6 so increment = 6