The relationship between temperature and resistance

The relationship between temperature and resistance

When it is a metal, the higher the temperature, the greater the resistance. The reason is that there are freely moving electrons inside. When the temperature rises, these electrons will vibrate back and forth intensified, so as to hinder the current. The higher the temperature of non-metallic substances (part of semiconductors), the lower the resistance. Reason: When the temperature rises, the internal electronic movement intensifies (but it will not vibrate back and forth), which can then carry electric charges.

For example, the resistance of metals always increases with the increase in temperature, because when the temperature increases, the thermal movement of molecules in the metal increases. When the conductor resistance is 1Ω, the temperature changes by 1°C, and the value of the resistance change is called the temperature coefficient of resistance. Constantan and manganin have a small temperature coefficient of resistance, and their resistance is hardly affected by temperature, so they are often used to make standard resistors or varistors.

When the temperature of some substances rises, the resistance of the positive and negative ions will increase, and the resistance will decrease, and the temperature coefficient of resistance will be negative.

Tests have proved that the resistance of any conductor changes when the temperature changes. For example, the resistance of metals always increases with the increase in temperature, because when the temperature increases, the thermal movement of molecules in the metal increases. When the conductor resistance is 1Ω, the temperature changes by 1°C, and the value of the resistance change is called the temperature coefficient of resistance. Constantan and manganin have a small temperature coefficient of resistance, and their resistance is hardly affected by temperature, so they are often used to make standard resistors or varistors.