Positive SSL
    14.素養(4)
1 若電壓v(t)=50sin(ωt+45°)V,電流i(t)=50cos(ωt-45°)A,則下列何者正確? 100 統測
A v領先i 90°
B v落後i 90°
C v領先i 180°
D v與i同相

cosθ=sin(θ+90°)

i(t)=50cos(ωt-45°)A => i(t)=50sin(ωt-45°+90°)A => i(t)=50sin(ωt+45°)A

故v、i同相