1 Answer
The resistance of a conductor is affected by temperature. In general, for most conductors (like metals), the resistance increases with an increase in temperature. Here's how and why:
1. Movement of Electrons:
- Conductors allow electric current to flow because of free-moving electrons. These electrons move through the metal's structure when an electric potential is applied.
- When the temperature increases, the atoms in the conductor vibrate more. This means the free electrons face more collisions with these vibrating atoms.
2. Increased Collisions:
- As the temperature rises, the increased atomic vibration causes the electrons to scatter more often. These collisions reduce the smooth flow of the electrons, which in turn increases the resistance.
3. Effect on Resistance:
- In most metallic conductors, as the temperature increases, the resistance increases because the rate of collisions between electrons and the atoms in the conductor becomes higher.
- This relationship is often expressed by the formula:
\[
R_T = R_0 (1 + \alpha T)
\]
where:
- \(R_T\) is the resistance at temperature \(T\),
- \(R_0\) is the resistance at reference temperature (usually 0°C),
- \(\alpha\) is the temperature coefficient of resistance (a material-specific constant),
- \(T\) is the temperature change in degrees Celsius.
4. Exceptions:
- Not all materials behave in the same way. For example, semiconductors behave differently: As the temperature increases, their resistance decreases. This happens because the number of charge carriers (electrons) in a semiconductor increases with temperature, allowing easier current flow.
Conclusion:
In most metals, increased temperature increases the resistance due to more frequent collisions between electrons and atoms. However, this effect is different for materials like semiconductors, which decrease in resistance as temperature increases.
1. Movement of Electrons:
- Conductors allow electric current to flow because of free-moving electrons. These electrons move through the metal's structure when an electric potential is applied.- When the temperature increases, the atoms in the conductor vibrate more. This means the free electrons face more collisions with these vibrating atoms.
2. Increased Collisions:
- As the temperature rises, the increased atomic vibration causes the electrons to scatter more often. These collisions reduce the smooth flow of the electrons, which in turn increases the resistance.3. Effect on Resistance:
- In most metallic conductors, as the temperature increases, the resistance increases because the rate of collisions between electrons and the atoms in the conductor becomes higher.- This relationship is often expressed by the formula:
\[
R_T = R_0 (1 + \alpha T)
\]
where:
- \(R_T\) is the resistance at temperature \(T\),
- \(R_0\) is the resistance at reference temperature (usually 0°C),
- \(\alpha\) is the temperature coefficient of resistance (a material-specific constant),
- \(T\) is the temperature change in degrees Celsius.