Ok i did an experiment using an oscilloscope, pulse generator and and RC set up circuit.
The graph on the oscilloscope showed a DC relationship for R and C (exponential etc).
Though i thought those equipments we used were for AC and not DC.
Also, we were asked how the voltage amplitude would change with frequency increases, which would suggest AC would it not? Would a DC increase in voltage amplitude if the frequency were increased, if so why?
Hope you can clear my confusion (particularly with the frequency part!)
The graph on the oscilloscope showed a DC relationship for R and C (exponential etc).
Though i thought those equipments we used were for AC and not DC.
Also, we were asked how the voltage amplitude would change with frequency increases, which would suggest AC would it not? Would a DC increase in voltage amplitude if the frequency were increased, if so why?
Hope you can clear my confusion (particularly with the frequency part!)
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exponential is not DC (or AC), it is exponential. DC means not changing.
Yes, any mention of frequency means AC.
DC does NOT have frequency, it is an unchanging voltage. Frequency is the rate at which a waveform repeats itself, and only applies to AC.
"Would a DC increase in voltage amplitude if the frequency were increased" makes no sense, sorry.
Hope this helps. email me if not.
.
Yes, any mention of frequency means AC.
DC does NOT have frequency, it is an unchanging voltage. Frequency is the rate at which a waveform repeats itself, and only applies to AC.
"Would a DC increase in voltage amplitude if the frequency were increased" makes no sense, sorry.
Hope this helps. email me if not.
.
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An oscilloscope will show both components AC and DC of any wave form.
It will also give you the amplitudes of each component as well as the frequency of the AC component.
If you change the frequency in a RC circuit you change the Capacitive Reactance, (Xc) which changes the impedance (Z) of the circuit, which ultimately will change the voltage drop across the RC network.
Xc = 1 / 2Pi.f.C. (I think, from 50+ years ago at college). God that's a long time in'it?
DC can have a frequency. A square wave, purely on the positive side of zero volts, has a frequency of on off pulses. DC is not necessarily a steady state voltage, but an average of the positive wave.
It will also give you the amplitudes of each component as well as the frequency of the AC component.
If you change the frequency in a RC circuit you change the Capacitive Reactance, (Xc) which changes the impedance (Z) of the circuit, which ultimately will change the voltage drop across the RC network.
Xc = 1 / 2Pi.f.C. (I think, from 50+ years ago at college). God that's a long time in'it?
DC can have a frequency. A square wave, purely on the positive side of zero volts, has a frequency of on off pulses. DC is not necessarily a steady state voltage, but an average of the positive wave.
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for dc a capacitor is just an open circuit just like inductor is a short circuit. but for sine signals reactivity(imaginary counterpart of resistance) is given by Xc=-1(2pi*f*C) and Xl=2pi*f*L
reactance is also measured in ohms and in ac circuits current is flowing through reactances same way it moves through resistances. oscilloscopes have no particular trouble measuring dc btw, you can, it just shows you straight line at given voltage. also there are signals that cant be classified ac or dc, simplest example: digital signals. pulses etc. there the rc time constant(simply multiply r and c you have, the result is in seconds and shows you how fast the capacitor charges and discharges) matters more
reactance is also measured in ohms and in ac circuits current is flowing through reactances same way it moves through resistances. oscilloscopes have no particular trouble measuring dc btw, you can, it just shows you straight line at given voltage. also there are signals that cant be classified ac or dc, simplest example: digital signals. pulses etc. there the rc time constant(simply multiply r and c you have, the result is in seconds and shows you how fast the capacitor charges and discharges) matters more