Homework Help: RC circuit voltage

1. Nov 4, 2007

dizi100

Why the voltage across the capacitor can be measured by connecting a CRO across both the resistor and capacitor ?

actually,i have think of the phase difference and the overall resistance.Still,i can't find the answer.May I get some hints from you?

Last edited: Nov 4, 2007
2. Nov 4, 2007

Astronuc

Staff Emeritus
How else would one propose to measure the voltage across a RC cirucit as a function of time, especially for short time constants?

Using a CRO (oscilloscope) is pretty standard. Of course, the impedance of the CRO needs to be high enough so as not to effect the measurement.

3. Nov 4, 2007

dizi100

For ac voltage,voltage of the power supply equals voltage across both capacitor and resistor.
If i connect a CRO across both capacitor and resistor,i in fact measure the voltage of the power supply,right?
According to my lab manual,it states that i can mesure the voltage across the capacitor by connecting a CRO across the capacitor and resistor.
i really dont understand...