Cdu 9: Cho doan mach di$n xoay chieu gom cuon day c6 dien trd thuan R , m^c nol tiep v6i tu*dien Biet hieu dien the giffa hai dau cuon day lech pha — so v6i hi|u dien the giuTa hai dau doan mach Moi lien h$ giiJa dien tror thuan R vdri cam khang Z L cua cuon day dung khdng Zc cua tu dien la: ' D R=^ = ZC(ZL - C R ' = Zc(Zc - ZL) ' E R2 = ZL(ZC - Z L ) A R ' = ZL(ZL - Zc) Zc) Do lech pha giffa hai dau cuon day: tancp, = —^ R Z Do l$ch pha giffa hai dau doan mach: tan(p = — -Z - R Theo gia thiet 9, +(p = — nen ta c6: cot(p, =tan(p =>^=^^-^R^=z,(z,-zJ Vdy chqn dap an B Cdu 10: Hat nhan ^^X ph6ng xa bien mot hat nhan ^^^Y ben Coi khoi lifcfng cua hat nhan X , Y bang so khoi cua chung tinh theo dcfn v i u Biet chat phong xa X c6 chu k i bdn 1^ T Ban dau c6 mot khoi lifcfng chat ^^X, sau chu Id ban t h i t i so giffa khoi Iffdng cua chat Y A - ^ Aj khoi lUcfng cua chat X la: B ^ A, C ^ A, Sau chu kX, so hat nh^n X c6n lai 1^: D = T i so' kho'i Ifftfng cha't Y • • X la: = 3^ Aj = So hat nhan cua chat Y hinh th^nh la: N„ = N * Vdy chon dap an B N^A, ^ = -N^ = 3^ A, ^ G i i c h i l i S t ( J « t h i T S B H , C D M n V$t«