RL串联电路R=40Ω,L=0.03H,外加电压u=10√2sin(1000t)V.则电路阻抗Z=(____)。
A30∠36.9°Ω$;$40∠36,9°Ω$;$50∠36.9°Ω$;$70∠36.9°Ω
B30∠36.9°Ω$;$40∠36,9°Ω$;$50∠36.9°Ω$;$70∠36.9°Ω
C30∠36.9°Ω$;$40∠36,9°Ω$;$50∠36.9°Ω$;$70∠36.9°Ω
D30∠36.9°Ω$;$40∠36,9°Ω$;$50∠36.9°Ω$;$70∠36.9°Ω