Examp!e2: Find Uoc andrin·「 2K 3k 十 Solution 1. Find v 4000 U.=4+2000× 4000∴D=Ux=8 2. Find rth (A): Method of short-circuit current(电源保留).Rm 2k 3 R U 4000 8 U,=U=0, =0.8mA. Rh=. 10kg2 000 sk 8×10Solution: 1.Find voc. (A): Method of short-circuit current(电源保留). oc x V x x , 8 4000 = 4+ 2000   = =   0.8 . 5 4 0, 4000 0, mA k i s c x x = =  =  = =    =   = = − k i R sc oc th 10 0.8 10 8 3  Example 2: Find  OC and . Rth 2. Find Rth.  sc i 4000  x − +  x 2k 3k − + 4V 4000  x − +  x 2k 3k − + 4V  oc Rth sc i − +  − + sc oc th i R  =