Frequency Index Compares to Cutoff - Electronic Circuits VII: Frequency Response and Filters Step by Step

A filter lesson starts by comparing a signal frequency to a cutoff. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Frequency is compared to the cutoff

The signal frequency is 6 hertz and the cutoff is 12 hertz.

x = {f \over f_c} = {6\over 12}

The normalized index is exact

The normalized frequency index is 1/2.

x = {1\over 2}