RL low pass filter
f_cutoff = R / 2πL = 79.6 kHz (about 80 kHz).
(with L = 100μH and R = 50Ω)
When running the AC voltage source at 80kHz 1V RMS (green), the voltage across the resistor is 0.707V RMS.
Change the frequency of the source and see the voltage across the resistor drop.
