RL Circuits

Discussion in 'Homework Help' started by jtyler, Feb 2, 2010.

  1. jtyler

    Thread Starter New Member

    Feb 2, 2010
    AC voltage supply (3.53 Vrms, 2 kHz) with 33mH inductor in series with a 470 ohm resistor.
    (inductor resistance = 50 ohms)

    Change AC input frequency to 1 kHz then 500 Hz then 250 Hz.
    Change AC input frequency to 5 kHz then 10 kHz then 20 kHz.

    For each new frequency indicate whether the voltage measured (VR) and (VL) decreased, increased or did not change compared to the 2 kHz input frequency.
    Last edited: Feb 3, 2010
  2. beenthere

    Retired Moderator

    Apr 20, 2004
  3. hondabones

    Senior Member

    Sep 29, 2009
    In the first set of frequencies they are decreasing by half each time. When the frequency decreases the reactance decreases. When the reactance decreases the impedance decreases. Impedance decreasing means the total current increases. This means that VR increases.

    This type of problem is a matter of plugging in the numbers into 4 - 5 equations used for this situation and repeatedly getting values and comparing them to see the results.