正弦交流电压有效值为220v,频率为50Hz,t=0时,u(0)=220V,则该正弦电压表达式为
A.u=220sin(314t+45°)V B.u=311sin(50t+135°)V C.u=31lsin(314t-45°)V D.u=311sin(314t+45°)V正确答案D
正弦交流电压有效值为220v,频率为50Hz,t=0时,u(0)=220V,则该正弦电压表达式为
A.u=220sin(314t+45°)V B.u=311sin(50t+135°)V C.u=31lsin(314t-45°)V D.u=311sin(314t+45°)V正确答案D