... Cau 10 0: 2n f^ = ^]2n yjg 39 yj 1- 7,9 At , ^r-^ = — -»/ = 15 1,1cm 9 40 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 11 0 B A A B B C C A C B 11 1 11 2 11 3 11 4 11 5 11 6 11 7 11 8 ... 0, 012 5 s, f = i = 80Hz b. = VjT = 330 X 0, 012 5 = 4 ,12 5 m — — — — 1 — ^ — 1 An ^' Xi ~ vT ~ T ~ 0, 012 5 ~ d. = VzT = 14 52 X 0, 012 5 = 18 ,15 m Bai tap 1: ... 20dB 10 Ig^ = 20 => /z = lOO/i Cau 11 : /, = 10 00 /1 =» L2 - ^1 = 10 Ig^ = 30dB &apos ;1 Cau 12 : - LB = 10 Ig^ => 90 - 70 = 10 Ig^ => ^ = 10 0 Cau 13 : - = 10 Ig^...