5.如【圖 5】所示,圖(b)為圖(a)的等效電路,則其 RTH與 ETH分別為多少?
(A) RTH =12/11 Ω、ETH = 2.4 V(B) RTH =4/3 Ω、ETH = 8 V
(C)RTH =4 Ω、ETH = 6 V(D) RTH =8/3 Ω、ETH = 4 V