.PS include(pstricks.m4) scale=25.4 cct_init vsp=25 hsp=25 define(`termrad_',`sourcerad_/4') define(`terminal',`circle rad termrad_') O: (0,0) move to O VS: source(up_ vsp,V);llabel(,v_s,);rlabel(,90\;\text{V},) { dot(at Here) line up vsp*.75 R1: resistor(right_ hsp);llabel(,R_1,);rlabel(,100\;\Omega,) line down to (Here.x,VS.end.y) dot(at Here)} IS: source(right_ to (R1.end.x,Here.y),I,);llabel(,i_s,);rlabel(,\np{1.5}\;\text{A},) { line right hsp*.75 TA: terminal} dot(at Here) R2:resistor(down_ to (Here.x,O.y));rlabel(,R_2,);llabel(,500\;\Omega,) dot(at Here) { line right hsp*.75 TB: terminal} line to O "$a$" at TA.n above "$b$" at TB.s below "$+$" at TA.s below "$-$" at TB.n above "$v_{ab}$" at 1/2 between TA and TB .PE