# Calculating 3dB frequency.

1. Homework Statement

Using your results, calculate the 3dB frequency of the RC filter.

3. The Attempt at a Solution

Basically in our lab, we made a simple series RC low pass filter. We put in a 16V peak to peak signal at varying frequencies below, and measured the output voltage at the capacitor (again peak to peak) on the scope. Now if I want to calc the 3dB frequency from my results, would I plot this on a graph and look for the 3dB point? I have tried this, but I think I am going wrong somewhere. The second table would be what Im trying to plot. I took first column is just the log of the frequency. The second column is 10log(Vout/Vin). It just doesnt seem right.

fin (Hz) Vo (V)
50 13.8
100 11.4
150 9.6
200 8.2
250 7.2
300 6.4

1.698970004 -0.749974923
2.000000000 -1.579527115
2.176091259 -2.326214759
3.301029996 -3.010299957
2.397940009 -3.665315444
2.477121255 -4.087127349

sorry for the formatting!

Related Engineering and Comp Sci Homework Help News on Phys.org
AlephZero