2.\(R = 4\Omega\) 與 \(X_C = 3\Omega\)串聯在電源E=100V,f=60HZ。若頻率改為 (f')=120HZ,則新的容抗(X'c)及新的電阻(R')各為多少?(A) \(X_c' = 1.5\Omega\), \(R' = 4\Omega\) (B) \(X_c' = 3\Omega\), \(R' = 2\Omega\) (C) \(X_c' = 6\Omega\), \(R' = 8\Omega\) (D) \(X_c' = 9\Omega\), \(R' = 5\Omega\)