!Measuring Currents in a Circuit w/ Semiconductor

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Discussion Overview

The discussion revolves around measuring currents in a circuit that includes a semiconductor, focusing on the concepts of conduction and displacement currents. Participants explore the implications of switching the circuit off rapidly and the resulting effects on current measurements.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant questions what would be measured by an ammeter in a circuit with a semiconductor, specifically whether it would show zero total current or the value of the conduction current.
  • The same participant describes a scenario where a current source, ammeter, switch, and semiconductor are involved, noting that the semiconductor can exhibit both conduction and displacement currents.
  • The participant suggests that when the circuit is switched off rapidly, the conduction current must cancel the displacement current to achieve a total current of zero.
  • Another participant points out a potential misunderstanding regarding the thread title, suggesting it may have been truncated and clarifying the intended question about the relationship between displacement and conduction currents.
  • A subsequent reply acknowledges the correction and indicates that the original post was based on a misunderstanding, leading to its deletion.

Areas of Agreement / Disagreement

The discussion includes some clarification on the thread title but does not reach a consensus on the original question regarding the relationship between conduction and displacement currents.

Contextual Notes

The discussion lacks detailed definitions of conduction and displacement currents, and the assumptions regarding the behavior of the circuit during the switching process are not fully explored.

Dor
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If so, what will I measure in the Ampermeter, the zero total current or the value of the conduction current?

I was thinking of the following example- a circuit consist of a current source, an Ampermeter, a switch, and a semiconductor. The semiconductor can have both conduction and displacement currents since it is a dielectric conductor. At some point in time I'm switching off the circuit (infintly fast) and so the current at the outer circuit is zero. The electric field will change in time thus there will be a displacement current. To make the total current zero, the conduction current needs to cancel the displacement current. Is this description true? Thanks
 
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I think your title
"Can the displacement current be equal to and opposite in sign to the c"
has been truncated. So, it might seem [at a quick glance] that you are asking about the speed of light, c.

I think the full title is something like
"Can the displacement current be equal to and opposite in sign to the conduction current?"
 
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Sorry Dale and thank you robphy for drewing my attention. I've edited the title to a more reasonable one
 
No problem! Since my post was based on a mistaken understanding I have deleted it.
 
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