Hello every9one i'm stuck on finding the first part: A series RLC circuit is driven by an alternating source at a frequency of 380 Hz and an emf amplitude of 90.0 V. The resistance is 20.0 , the capacitance is 12.1 µF, and the inductance is 24.2 mH. What is the rms potential difference across the resistor? my first answer was wrong, Am i t hinking this right? Vab = Vmax sin(wt) Vab = iR i = 90/20 = 4.5, but thisn't isn't i max is it? do i have to take i/sqrt(2) to get i max? then with i max can i find the rms across the ressitor? I found a formula that syas: Vab = Vmax*sin(wt) but time isn't given at all, netiehr isVmax!