Low Pass: Why did my professor use frequency and not angular frequency?

AI Thread Summary
The discussion centers on a homework problem involving a passive RC low pass filter, where the professor used frequency (f) instead of angular frequency (ω) in calculations. The student notes that the correct relationship should be ω = 2πf, leading to confusion regarding the professor's solution. Despite successfully calculating the output voltage magnitude and phase angle, the student questions the validity of using f in place of ω. The consensus suggests that this might be a clerical error, as the professor typically uses the correct formula in other examples. Clarification on this point is sought to ensure understanding of the concepts involved.
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Homework Statement



We are given a passive RC low pass filter with an input voltage of 5 Vrms at a frequency of 1 kHz. The resistor has a value of 22 kΩ, the capacitor a value of 100 nF. There is a current i across the resistor. (see picture below)

We are to calculate the magnitude and phase angle of the output voltage.

By the way, in the picture below is in german, so V eff means rms, I think the rest should be apparent.

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Homework Equations



UR = R*I

Uout = I*XC

XC = I / ω*C

ω = 2*π*f (in rad/s)

The Attempt at a Solution



Analytically, this is not a problem, and I have attached the solution from the professor. My only problem is that for ω the professor used the frequency f, and not 2πf. As in:

ω = f = 1 kHz

This makes no sense to me and seems wrong. Could somebody possibly clarify what´s going on here? Thanks in advance.
 
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Seems wrong to me as well. I got 0.36V.
 
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CWatters said:
Seems wrong to me as well. I got 0.36V.

I think this must be a clerical mistake, as in all of the other examples he uses ω = 2πf. Thanks a bunch for checking! :oldsmile:
 
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