Question

Q. In Excel, set the resistor value at 10 ohms an d then vary the capacitance (C) so you can clearly see the cut off impact of the filter (plot F on y-axis and C on x axis). Use a minimum of least 2 orders of magnitude. Label axis, Print out plot. ). Use a minimum of 1,000 C values that spread over at

Answer 1

The cut-off frequency of a low pass filter (RC) filter shown in the diagram below is given by,

$f_{c}= \frac{1}{2\pi RC}$ ,

where R and C are the values of resistance and capacitance used in the RC circuit.

aut &T R

As per the question, I varied the Capacitance from 1 Farad to 1000 Farad and Resistance was kept at 1 Ohm as constant. The formula for cutoff frequency was fed into one column of an excel sheet and corresponding cutoff frequency was produced. This was plotted as given in the graph below.

The following formula was loaded to the first column of the table in excel, and table for 1000 values was generated by pulling down both columns. (Note: 10 is for resistance and 3.1417 is for the value of pi)

Σ = -1/(2*3.1417*10°C7) fc 2 0.007957475

Using column C and D I plotted the following graph between frequency and Capacitance in Y and X axis respectively.

Capacitance VS Fc 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 200 400 600 800 1000 1200 Capacitan ce C (Farads)

Hope this helps.