Resistors become insulators at some high temp.

In summary: True, but I was merely point out to the OP, not to you of course, that there is indeed a relationship between temperature and resistivity amongst conductors as it seemed to be part of the inquiry.
  • #1
anonymoussome
59
0
Every conductor or insulator becomes/is believed to become perfectly conducting at o kelvin

Similarly every resistor should also have some upper limit i.e. it should become insulator at some very high temperature?
Is it so?
Please explain...
 
Physics news on Phys.org
  • #2
anonymoussome said:
Every conductor or insulator becomes/is believed to become perfectly conducting at o kelvin

No they don't! A semiconductor becomes more insulating as the temperature becomes lower. So your starting premise here is already false. This is one of the properties of a typical insulating material.

Zz.
 
  • #3
ZapperZ said:
No they don't! A semiconductor becomes more insulating as the temperature becomes lower. So your starting premise here is already false. This is one of the properties of a typical insulating material.

Zz.

Although this is true of semiconductors, I believe the OP was referring to metallic conductors, not semiconductors. In a metallic conductor, the electrical resistance tends to zero as the temperature tends to absolute zero.

Conversely, the electrical resistance will typically increase in a conductor as the temperature increases.

[tex]R = \frac{L}{A} \cdot \rho_0( \alpha(T - T_0) + 1) [/tex]

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/scond.html#c1

http://en.wikipedia.org/wiki/Ohm's_law

CS
 
  • #4
stewartcs said:
Although this is true of semiconductors, I believe the OP was referring to metallic conductors, not semiconductors. In a metallic conductor, the electrical resistance tends to zero as the temperature tends to absolute zero.

But even that is only true for idealized conductors. In real metals the conductivity will saturate at relatively high temperatures, often tens of K. The reason is simply that it is only the phonon scattering that depends on the temperature, at low temperatures scattering against impurities, grain boundaries etc will start to dominate and these processes are essentially temperature independent and sets a limit for the conductivity.
 
  • #5
f95toli said:
But even that is only true for idealized conductors. In real metals the conductivity will saturate at relatively high temperatures, often tens of K. The reason is simply that it is only the phonon scattering that depends on the temperature, at low temperatures scattering against impurities, grain boundaries etc will start to dominate and these processes are essentially temperature independent and sets a limit for the conductivity.

I know, that's why I said tends to zero and not is zero.

CS
 
  • #6
stewartcs said:
Although this is true of semiconductors, I believe the OP was referring to metallic conductors, not semiconductors. In a metallic conductor, the electrical resistance tends to zero as the temperature tends to absolute zero.

Conversely, the electrical resistance will typically increase in a conductor as the temperature increases.

[tex]R = \frac{L}{A} \cdot \rho_0( \alpha(T - T_0) + 1) [/tex]

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/scond.html#c1

http://en.wikipedia.org/wiki/Ohm's_law

CS

I'm not sure how this is relevant to what I said. Note the OP:

Every conductor or insulator becomes/is believed to become perfectly conducting at o kelvin

I wasn't addressing conductors. I was addressing insulators/semiconductors. That's why I said that whole premise is false. Insulators do not behave the same way as metals as far as temperature dependence goes.

BTW, I'm a condensed matter physicist, just so you know that I'm well aware of "Ohm's law" and temperature dependence of resistivity.

Zz.
 
Last edited:
  • #7
ZapperZ said:
I'm not sure how this is relevant to what I said. Note the OP:

I wasn't addressing conductors. I was addressing insulators/semiconductors. That's why I said that whole premise is false. Insulators do not behave the same way as metals as far as temperature dependence goes.

BTW, I'm a condensed matter physicist, just so you know that I'm well aware of "Ohm's law" and temperature dependence of resistivity.

Zz.

True, but I was merely point out to the OP, not to you of course, that there is indeed a relationship between temperature and resistivity amongst conductors as it seemed to be part of the inquiry.

CS
 

1. What is the temperature at which resistors become insulators?

The temperature at which resistors become insulators varies depending on the type of resistor and its materials. Generally, the transition occurs at high temperatures above 1000 degrees Celsius.

2. Why do resistors become insulators at high temperatures?

At high temperatures, the atoms in the resistor vibrate more vigorously, causing an increase in collisions between electrons and atoms. This increased collision rate makes it harder for electrons to move through the resistor, leading to a decrease in electrical conductivity and the resistor becoming an insulator.

3. Can all resistors become insulators at high temperatures?

No, not all resistors can become insulators at high temperatures. Some resistors are designed to withstand high temperatures and maintain their electrical conductivity, while others may have a lower tolerance for heat and become insulators at lower temperatures.

4. What are the potential risks of resistors becoming insulators at high temperatures?

If a resistor becomes an insulator at high temperatures, it can disrupt the flow of electricity and cause issues in electronic circuits. It can also lead to overheating and damage to the resistor itself, as well as other components in the circuit.

5. How can resistors be protected from becoming insulators at high temperatures?

To prevent resistors from becoming insulators at high temperatures, they can be made with materials that have a high melting point and good thermal conductivity. Additionally, proper heat dissipation measures, such as using heat sinks or increasing air flow, can help keep resistors within their safe temperature range.

Similar threads

  • Electromagnetism
Replies
17
Views
934
  • Introductory Physics Homework Help
Replies
2
Views
221
Replies
7
Views
1K
Replies
46
Views
2K
  • Thermodynamics
Replies
33
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
270
  • Thermodynamics
Replies
5
Views
980
  • Other Physics Topics
Replies
16
Views
11K
Replies
6
Views
1K
Replies
7
Views
1K
Back
Top