An 50.0 ohm resistor and a 200-mH inductor are connected in parallel across a 100-V (rms), 60.0 Hzsource.(a) What is the rms current in the resistor?(b) By what angle does the total current lead or lagbehind the voltage?
A) Current in resistor (100 V) / (50 Ohms) 2 Amps (RMS) B) Inductive reactance: 2 Pi f L 2 Pi (60 Hz)(0.2 H) 75.4 Ohms Impedance of parallel combination Z (75.4 i)(50) / ( 75.4i + 50 ) 34.7 + 23.0i 41.7 Ohms at 33.5 degrees The total current is therefore (100V) / Z 2.4 Amps at -33.5 degrees
Ir100/502 XL377*.275.4 Il100/(j 75.4) ItIr+il You do the math.
A) VrmsIrms*R therefore Irms Vrms/ R Vrms Vmax (sqrt2) Irms (100)/(50) 2 A B) Since we are talking about a inductor, it will lead by 90 degrees
