Understanding the Importance of Resistors in Electrical Circuits - Explained

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Discussion Overview

The discussion centers on the role and necessity of resistors in electrical circuits, particularly in relation to the resistance of wires. Participants explore the implications of wire resistance and the specific functions of resistors in circuit design.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions why resistors are necessary if wires themselves have resistance, suggesting that this is a common misunderstanding.
  • Another participant confirms that all materials, except superconductors, have resistance, but notes that the resistance of wires is often negligible in calculations for most circuits.
  • A participant challenges the notion that resistors are only for computational ease, proposing that wire resistance could be treated similarly to resistor resistance.
  • In response, another participant argues that wire resistance is typically very low, which can lead to circuit issues, such as overheating or sparking when discharging capacitors.
  • One participant humorously defines wire as a "Wicked Infinitesimal Resistance Element," suggesting that wires can have sufficient resistance in certain contexts, like a lightbulb filament.
  • Another participant states that resistors are necessary when a specific resistance value is required, which often exceeds that of a simple wire.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of resistors versus the resistance of wires. While some agree that wires do have resistance, there is no consensus on whether resistors are solely for computational purposes or if they serve additional regulatory functions in circuits.

Contextual Notes

Participants mention the practical implications of wire resistance in circuit design, but there are unresolved questions regarding the extent to which wire resistance can be considered in calculations and the specific scenarios where resistors are essential.

Who May Find This Useful

This discussion may be useful for individuals interested in electrical engineering, circuit design, or those seeking to understand the fundamental principles of resistance in electrical components.

cscott
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A question I've never had fully answered:-

Why are resistor(s) necessary in a circuit in the sense that wires themselves (in my mind) should have resistance since they constitute material just like resistors themselves?

Thanks
 
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cscott said:
A question I've never had fully answered:-

Why is are resistor(s) necessary in a circuit in the sense that wires themselves (in my mind) should have resistance since they constitute material just like resistors themselves?

Thanks
I think what you asking is that shouldn't the wires in a circuit have a resistance?

The answer is of course, yes! All materials (except super conductors) have a resistance and therefore should technically be accounted for in calculations. However, such calculations become tedious and generally, since wires are good conductors the error in ignoring the resistance of the wiring is negligible. There are some cases, such as power lines, where the resistance of the cabling must be taken into account.
 
But doesn't this imply that we add resistors to a circuit just for computational ability?

Can I consider a circuit with a capacitor and a wire taken with capacitance C and and resistance R?

Why can't the resistance of the wire take [tex]R= \rho \cdot \frac{L}{A}[/tex] like a "resistor" that we'd typically use?
 
It can be, but this is a ridiculously low resistance in almost all cases. Therefore you're likely to mess up your circuit somehow. When you try to discharge a capacitor through just a wire, you will see sparks fly. Hook just wire up to a battery, and it will heat up very quickly and drain the battery. Resistors serve to regulate the flow of current, not for computational ability.
 
WIRE = Wicked Infinitesimal Resistance Element.

Sometimes, a wire has sufficient resistance on it's own- a lightbulb filament is an example.
 
Resistors are necessary in electronic circuits when the value, or amount, of specific resistance to electron flow is needed. This oftentimes exceeds the amount of resistance of a simple "wire"
 
I get it now. Thanks all.
 

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