I have just done an experiment on CR and LR circuits
Connect channel 1 of the CRO across both the capacitor and resistor and channel 2 across the resistor.The trace on channel 1 is taken as the p.d. across the capacitor and that on channel 2 as ths current throught the capacitor.
Replace the capacitor waith a high inductance coil fitted on a double C-core.
I have some questions about this.
What is the Phase difference and why phase difference not equal to 90o
Also, why the channel 2 of the CRO give the current through the capacitor??
Phase difference in CR and LR
2010-01-03 6:09 am
回答 (3)
2010-01-08 6:13 am
無最佳解答
2010-01-03 8:10 am
Q: What is the Phase difference and why phase difference not equal to 90o
Your channel 1 is connected across both the capacitor and resistor. Now you have replaced the capacitor by an inductor. That is, channel 1 is connected across the both inductor and the resistor. Hence, channel 1 is actually measuring the voltage of the supply ac source. The phase angle between the supply voltage and the current (measured by channel 2) is never 90 degrees because of the presence of the resistor.
[Note: even if you connect channel 1 across the inductor, the phase difference with channel 2, the current, is still not exactly equal to 90 degrees because of the dc resistance of the inductor.]
The actual phase difference depends on the values of resistor and inductor used in the experiment.
Q: why the channel 2 of the CRO give the current through the capacitor??
The CRO measures the voltage across the resistor. By Ohm's Law, the current flows through the resistor is proportional to the voltage across it. Thus, measuring the voltage would give the current.
Your channel 1 is connected across both the capacitor and resistor. Now you have replaced the capacitor by an inductor. That is, channel 1 is connected across the both inductor and the resistor. Hence, channel 1 is actually measuring the voltage of the supply ac source. The phase angle between the supply voltage and the current (measured by channel 2) is never 90 degrees because of the presence of the resistor.
[Note: even if you connect channel 1 across the inductor, the phase difference with channel 2, the current, is still not exactly equal to 90 degrees because of the dc resistance of the inductor.]
The actual phase difference depends on the values of resistor and inductor used in the experiment.
Q: why the channel 2 of the CRO give the current through the capacitor??
The CRO measures the voltage across the resistor. By Ohm's Law, the current flows through the resistor is proportional to the voltage across it. Thus, measuring the voltage would give the current.
2010-01-03 6:53 am
Phase difference of what?
which compared to which?
which compared to which?
收錄日期: 2021-04-29 17:35:06
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