... Cho bit U, R, L, C: tỡm f ( hay ) UR , UL hay UC t giỏ tr cc i? 49 1.Tỡm f ( hay ) hiu th hiu dng hai u in tr cc i 49 2.Tỡm f ( hay ) hiu th hiu dng hai ... Vt Lý 12 www.VNMATH.com Trng THPT - Phong in Ch Cỏch ỏp dng nh lut bo ton nng lng mch dao ng LC 58 1.Bit Q0 ( hay U0 ) tỡm biờn I0 58 2.Bit Q0 ( hay U0 )v q ( hay ... = ZL ZC = L = hay tg = R C Hay LC = 3.Cụng sut tiờu th trờn on mch cc i: Ta cú: P = U I cos , P = max cos = R Ta cú: cos = =1 R2 + (ZL ZC )2 Hay R2 + (ZL ZC )2 = R2 Hay LC = 4.Kt lun:...