試卷名稱:112年 - 112 學士後醫學系招生考試:物理及化學#114227
年份:112年
科目:學士後西醫物理及化學
50. Two long straight current-carrying parallel wires cross the x axis and carry currents I and 3I in the same direction, as shown in the figure. At what value of x is the net magnetic field zero?
(A) 1
(B) 3
(C) 4
(D) 5
(E) 7