resistors and inductors in series add up R12R1+R2 resistors and inductors in parallel dont: 1/R121/R1 + 1/R2 or R121/[(1/R1) + (1/R2)] or R12R1*R2/(R1+R2) remember this formula, it will be time saver on tests (even if it only for two elements) for capacitors it is the opposite: parallel capacitors add up C12C1+C2 series capacitors dont: C12C1*C2/(C1+C2) a) Inductors - output is open circuit (nothing connected to it). in this case D and B are in, series DBD+B. this is in parallel with A, so ADB AD*B/(AD+B) this ADB is then in series with C so we get ABCD ADB+C using given numbers we get Ldb4+26H La1H Ladb6*1/(6+1)6/7H0.857H Lc3H Labcd3+0.8573.857H now the output is shorted and B and C are in parallel: LbcLb*Lc/(Lb+Lc)2*3/(2+3)6/5H1.2H this is then in series with A so LabcLa+Lbc1H+1.2H2.2H finally this is in parallel with D so LabcdLabc*Ld/(Labc+Ld)2.2*4/(2.2+4) b) capacitors, first output is open: you get Cb in series with Cd. this is then in parallel with Ca. finally Cabd is in sereis with Cc. numerical results will match second part of a. then output X-Y is shorted and you get Cb and Cc in parallel CbcCb+Cc. This is in series with Ca CabcCa*Cbc/(Ca+Cbc) finally this is in parallel with Cd. CabcdCd+Cabc and results must match first part of a.
