-In a low-pass RC filter, having a cutoff frequency of 2 kHz, C = 80nF. Determine R.
A) 98.0 Ω
B) 44.7 Ω
C) 995 Ω
D) 22.7 Ω

Question

-In a low-pass RC filter, having a cutoff frequency of 2 kHz, C = 80nF. Determine R.
A) 98.0 Ω 
B) 44.7 Ω 
C) 995 Ω 
D) 22.7 Ω

Quizplus · Accepted Answer

The cutoff frequency $f_c$ of a low-pass RC filter is given by $f_c = \frac{1}{2\pi RC}$. Rearranging for R gives $R = \frac{1}{2\pi f_c C}$. Substituting $f_c = 2000$ Hz and $C = 80 \times 10^{-9}$ F, $R = \frac{1}{2\pi \times 2000 \times 80 \times 10^{-9}} \approx 995$ Ω.

-In a Low-Pass RC Filter, Having a Cutoff Frequency of 2