# RL Circuits

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

1. ### jtyler Thread Starter New Member

Feb 2, 2010
6
0
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

Apr 20, 2004
15,808
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3. ### hondabones Senior Member

Sep 29, 2009
123
1
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.