Resistance of a capacitor and inductor in a dc circuit

AI Thread Summary
In a DC circuit, an inductor behaves like a short circuit, resulting in very low resistance, while a capacitor acts as an open circuit, leading to very high resistance. The discussion emphasizes that at DC, inductors do not resist current flow significantly, and capacitors do not allow current to flow once charged. The confusion arises from the dynamic behavior of these components during changes in current or voltage. The correct answers for the resistance of an inductor and capacitor in a DC circuit are very low and very high, respectively. Understanding these principles is crucial for basic DC electronics.
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Homework Statement



From my Basic DC electronics text.

2 questions, multiple choice, but I seem to be able to talk myself into several of the options. I've combed the book thoroughly, and humbly come to you folks in sincere desperation.

The resistance of an/a Inductor/Capacitor in a DC circuit will be:


The Attempt at a Solution



For an Inductor

A. Very Low
B. Very High
C. Depend on it's inductance value
D. Depend on the voltage applied to the inductor

For this one I am pretty sure the answer would be A? As an inductor is little more than a wound wire with a core... but then I ask myself, well if it induces a counter emf, wouldn't it then be countering the current and acting somewhat as a resistor while the current is changing?

For a Capacitor

A. Very Low
B. Very High
C. Determined by the area of it's plates
D. Determined by the distance between it's plates

Here I want to circle very high, because a cap has a dielectric insulator that has a very high resistance, no? But then I say.. well current still flows once the thing is charged, and it might be dependent upon the spacing between the plates?

Any help would be greatly appreciated sirs or maams, thanks in advance to any kind soul who takes pity on me!
 
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orecets said:

Homework Statement



From my Basic DC electronics text.

2 questions, multiple choice, but I seem to be able to talk myself into several of the options. I've combed the book thoroughly, and humbly come to you folks in sincere desperation.

The resistance of an/a Inductor/Capacitor in a DC circuit will be:


The Attempt at a Solution



For an Inductor

A. Very Low
B. Very High
C. Depend on it's inductance value
D. Depend on the voltage applied to the inductor

For this one I am pretty sure the answer would be A? As an inductor is little more than a wound wire with a core... but then I ask myself, well if it induces a counter emf, wouldn't it then be countering the current and acting somewhat as a resistor while the current is changing?

For a Capacitor

A. Very Low
B. Very High
C. Determined by the area of it's plates
D. Determined by the distance between it's plates

Here I want to circle very high, because a cap has a dielectric insulator that has a very high resistance, no? But then I say.. well current still flows once the thing is charged, and it might be dependent upon the spacing between the plates?

Any help would be greatly appreciated sirs or maams, thanks in advance to any kind soul who takes pity on me!

Welcome to the PF!

Your answers are correct. The key to this question is the phrase "DC circuit". At DC, an inductor is a short (it's just a wire), and a cap is an open (two open plates facing each other).
 
Last edited:
Thank you much sir!

And thank you for the welcome too.

Ill be sure to "pay it forward" should someone come along with a remedial enough question
 
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