. ▁ ▁The ▁AC ▁load ▁line ▁is ▁a ▁straight ▁line ▁with ▁a ▁slope ▁equal ▁to ▁the ▁AC ▁imped ance ▁facing ▁the ▁non linear ▁device , ▁which ▁is ▁in ▁general ▁different ▁from ▁the ▁DC ▁resistance . ▁ ▁The ▁ratio ▁of ▁AC ▁voltage ▁to ▁current ▁in ▁the ▁device ▁is ▁defined ▁by ▁this ▁line . ▁▁▁ ▁Because ▁the ▁imped ance ▁of ▁the ▁re active ▁components ▁will ▁vary ▁with ▁frequency , ▁the ▁slope ▁of ▁the ▁ ▁AC ▁load ▁line ▁depends ▁on ▁the ▁frequency ▁of ▁the ▁applied ▁signal . ▁ ▁So ▁there ▁are ▁many ▁AC ▁load ▁lines , ▁that ▁vary ▁from ▁the ▁DC ▁load ▁line ▁( at ▁low ▁frequency ) ▁ ▁to ▁a ▁limit ing ▁AC ▁load ▁line , ▁ ▁all ▁having ▁a ▁common ▁intersection ▁at ▁the ▁DC ▁operating ▁point . ▁This ▁limit ing ▁load ▁line , ▁generally ▁referred ▁to ▁as ▁the ▁AC ▁load ▁line , ▁is ▁the ▁load ▁line ▁of ▁the ▁circuit ▁at ▁" in finite ▁frequency ", ▁and ▁can ▁be ▁found ▁by ▁replacing ▁capac itors ▁with ▁short ▁circ uits , ▁and ▁induct ors ▁with ▁open ▁circ uits . ▁ ▁Load ▁lines ▁for ▁common ▁configurations ▁ ▁Trans istor ▁load ▁line ▁▁▁ ▁The ▁load ▁line ▁diagram ▁at ▁right ▁is ▁for ▁a ▁resist ive ▁load ▁in ▁a ▁common ▁em itter ▁circuit . ▁ ▁The ▁load ▁line ▁shows ▁how ▁the ▁collect or ▁load ▁res istor ▁( RL ) ▁const ra ins ▁the ▁circuit ▁voltage ▁and ▁current . ▁ ▁The ▁diagram ▁also ▁plots ▁the ▁trans istor ' s ▁collect or ▁current ▁IC ▁versus ▁collect or ▁voltage ▁V CE ▁for ▁different ▁values