A progressive wave gets reflected at a boundary such that the ratio of amplitudes of the reflected and incident wave is 1 :2. Find the percentage of energy transmitted .

A progressive wave gets reflected at a boundary such that the ratio of

1.	A progressive wave gets reflected at a boundary such that the ratio of amplitudes of the reflected and incident wave is 1 :2. Find the percentage of energy transmitted .
Answer» Solution :Given `(A_(r))/( A_(i)) = (1)/(2) rArr` RATIO of INTENSITIES is `(I_(1))/(I_(2)) = ((1)/(2))^(2)` Hence the fraction of energy transmitted `E_(1) = 1 - ((1)/(2))^(2) = (3)/(4)` The PERCENTAGE of energy transmitted ( of course PER unit time) is `3 //4 xx 100 = 75%`.