31. 如圖所示,若 E=100V,R=10kΩ,C=50nF,且電容器的初始電壓為 30V,當開關 S 閉合之瞬間,流經電阻的電流為多少? (A)1.1mA (B)1.8mA (C)3.5mA (D)7.0mA
7. Answer the questions based on the figure below. (8%)