Resistance of a capacitor and inductor in a dc circuit

In summary: I might be able to help withIn summary, the resistance of an inductor in a DC circuit will be very low, as it is just a wound wire with a core and does not significantly impede current flow. On the other hand, the resistance of a capacitor in a DC circuit will be very high, as it is essentially an open circuit with two plates facing each other. This is due to the fact that at DC, an inductor is a short and a capacitor is an open, making them both behave as ideal components.
  • #1
orecets
2
0

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!
 
Physics news on Phys.org
  • #2
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:
  • #3
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
 

Related to Resistance of a capacitor and inductor in a dc circuit

1. What is the difference between resistance and reactance in a DC circuit?

The resistance of a component in a DC circuit is the measure of how much it resists the flow of electric current. It is measured in ohms and is caused by factors such as the material and geometry of the component. Reactance, on the other hand, is the measure of how much a component affects the phase of the current in the circuit. In a DC circuit, this is typically caused by the capacitance or inductance of the component.

2. How do capacitors and inductors affect the flow of current in a DC circuit?

Capacitors and inductors are passive components that can store and release energy in a DC circuit. A capacitor stores energy in the form of an electric field, while an inductor stores energy in the form of a magnetic field. These components can affect the flow of current by introducing reactance, which can either delay or advance the phase of the current.

3. How does the resistance of a capacitor and inductor affect the overall resistance in a DC circuit?

In a DC circuit, the resistance of a capacitor is referred to as its leakage resistance, and the resistance of an inductor is referred to as its DC resistance. These resistances are typically much smaller than the resistance of other components in the circuit, such as resistors. Therefore, the overall resistance in a DC circuit is usually dominated by the resistance of the other components and not significantly affected by the resistance of the capacitor and inductor.

4. Can the resistance of a capacitor and inductor be measured directly in a DC circuit?

No, the resistance of a capacitor and inductor cannot be measured directly in a DC circuit. This is because the reactance of these components causes the current to lag behind the voltage, making it difficult to accurately measure the resistance using a simple ohmmeter. Instead, specialized equipment and techniques, such as impedance spectroscopy, are needed to measure the resistance of capacitors and inductors in a DC circuit.

5. How does temperature affect the resistance of a capacitor and inductor in a DC circuit?

The resistance of a capacitor and inductor in a DC circuit is affected by temperature just like any other component. However, the effect is typically minimal, especially for ceramic and film capacitors and ferrite-core inductors. This is because these components have low temperature coefficients of resistance, meaning that their resistance changes very little with changes in temperature. However, for other types of capacitors and inductors, the resistance may change more significantly with temperature.

Similar threads

Understanding a very simply RL circuit
    • Introductory Physics Homework Help
Replies
1
Views
198
Time dependant Potential Energy in ion trap
    • Introductory Physics Homework Help
Replies
1
Views
777
Find resistance of inductor in series RLC circuit
    • Introductory Physics Homework Help
Replies
5
Views
1K
What is happening in simple circuits with inductors and capacitors?
    • Introductory Physics Homework Help
Replies
2
Views
1K
The voltage across an AC source and a resistance in series
    • Introductory Physics Homework Help
Replies
4
Views
1K
Engineering Find di(0+)/dt and dv(0+)/dt of circuit containing resistor, inductor
    • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
Untangling a Confusing Circuit: Solving Kirchoff's DC Laws
    • Introductory Physics Homework Help
Replies
12
Views
1K
Engineering Find di/dt and dr/dt for a DC circuit with indepedent current source
    • Engineering and Comp Sci Homework Help
Replies
3
Views
3K
A circuit involving two non-linear resistances (incandescent lamps)
    • Introductory Physics Homework Help
Replies
14
Views
706
What represents the charge on a capacitor?
    • Electrical Engineering
Replies
2
Views
988

Hot Threads

Recent Insights

Back
Top