Why is there no voltage drop through this resistor?

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Discussion Overview

The discussion revolves around the observation of no voltage drop across a resistor in a circuit involving a capacitor, resistor, LED, and a battery. Participants explore the behavior of capacitors in this context, focusing on the implications of circuit configuration and component interactions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • The original poster (OP) describes a circuit where a capacitor, resistor, and LED are connected in series with a battery, noting specific voltage readings across the components.
  • Some participants suggest that the OP should discharge the capacitor and observe the circuit behavior without the LED to understand the voltage dynamics better.
  • One participant questions the OP's understanding of capacitors, implying that a lack of knowledge may be contributing to the confusion about the voltage drop across the resistor.
  • Another participant expresses frustration with the OP's understanding and challenges their grasp of the concepts involved.

Areas of Agreement / Disagreement

There is no consensus on the understanding of the circuit behavior, as some participants believe the OP lacks knowledge about capacitors, while the OP seems to feel they have received sufficient answers. The discussion reflects differing levels of understanding and interpretation of the circuit's operation.

Contextual Notes

The discussion does not resolve the underlying assumptions about the circuit's behavior, particularly regarding the role of the capacitor and the conditions under which the voltage drop is measured.

trickybilly
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I have wired in series: + of 9V battery --- + of 1000 uF capacitor --- 660 Ohm resistor --- + of a green LED --- - of the 9V battery. Remark: the 9V battery is a bit depleted 7.8 V unconnected.

Voltage drop across the capactor is 6.5V, across the LED is 1.5V but 0V across the resistor. Why there is no voltage drop across the resistor?
 
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Try this:
1) discharge the capacitor by placing the resistor across it for several seconds.
2) connect everything back up except the LED to - of the battery
3) connect the - of the battery while carefully watching the LED.

What did you see?

4) now remove the capacitor

What do you see now?

BoB
 
trickybilly said:
I have wired in series: + of 9V battery --- + of 1000 uF capacitor --- 660 Ohm resistor --- + of a green LED --- - of the 9V battery. Remark: the 9V battery is a bit depleted 7.8 V unconnected.

Voltage drop across the capactor is 6.5V, across the LED is 1.5V but 0V across the resistor. Why there is no voltage drop across the resistor?
Do you understand how capacitors work?

EDIT: Let me rephrase that: you clearly don't yet understand how capacitors work, so that's where you should focus. Study capacitors for a bit and you will understand what is happening in your circuit. That's where rbelli1 is leading you.
 
@phinds I have received my answer. Do YOU understand it?

2r7y9so.jpg
 

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trickybilly said:
Do YOU understand it?
You'll bite a helping hand ? Thanks for the warning.
 
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Since the OP has been answered we will close this thread. Everyone, please remember to be polite in future threads.
 
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