Calculating Cutoff Frequency with Oscilloscope and Coaxial Cable

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To calculate the cutoff frequency using an oscilloscope and coaxial cable, it's essential to consider the impedance of both components. The oscilloscope has an impedance of 1M Ohm and a capacitance of 25pF, while the coaxial cable has an impedance of 75 Ohm and a capacitance of 68pF/m. The discussion revolves around whether the resistance and capacitance from the coaxial cable are in series or parallel with the oscilloscope's impedance. Understanding the construction of capacitors and coaxial cables is crucial, as the capacitance in coaxial cables is determined by their inner and outer conductors, suggesting a parallel configuration. Clarifying these relationships will enable the calculation of the cutoff frequency and voltages at different frequencies.
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First take a look at the attachment (See reply below). We have to take the oscilloscope's impedance and the coaxial cable's impedance into account. And then we have to calculate the cutoff frequency of this.
Given: Oscilloscope: R=1M Ohm // C=25pF
Coaxial Cable: R=75 Ohm and C=68pF/m with L=0.85m
C=57.8pF

My problem is that I don't know how to draw this. R and C from the Coaxial cable, are they serial or parallel? And the coaxial cable's impedance is that serial or parallel to the oscilloscope's impedance?

If I know that, I can calculate the cutoff frequency and the voltages with different frequencies, but now I'm stuck. Thanks in advance.
 
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Attachment

And here's the attachment :).
 

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    cutofffreq.jpg
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Anyone? Or is my question not clear enough?
 
Here's a hint: What is a capacitor? In asking this I'm prodding you into thinking about how a capicitor is physically made from there you should be able to figure out the problem. Also, do you know what a coaxial cable is and how it is constructed? If you don't know google it. If you do know, think about the construction of the coax cable and that of a capacitor. Good Luck
 
Well a capacitor is actually two charged conductors very close to each other, so there's a voltage difference between them, right? And a coaxial Cable has an inner and an outer conductor, so those two conductors are responsible for the capacitance. That means the capacitance has to be parallel, right?

SO it has to be one of this two schemes (attached)?
Only I'm not sure which one...
 

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  • cutoffreq2.jpg
    cutoffreq2.jpg
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