38.依據克希荷夫定理，三個電阻並聯的等效電阻R的計算公式為下列何者？
(A)R = (R1×R2×R3)/(R1+R2+R3)  
(B)R = 1/R1+1/R2+1/R3  
(C)R = R1+R2+R3  
(D)R = 1/(1/R1+1/R2+1/R3)

答案：登入後查看
統計： A(11), B(8), C(3), D(35), E(0) #1197577