From a physical point of view, we analyze why the resistance value of the resistance wire increases

This is mainly related to the internal structure of the metal atoms and the way the atoms are bound together.

Metals (except mercury) are crystals at room temperature, and they have the characteristics common to crystals in terms of internal structure and properties, but metal crystals also have their unique properties, such as metallic luster and good electrical, thermal, and plastic conductivity. However, the fundamental difference between metals and nonmetals is that the resistance of metals increases with the increase of temperature, that is, the resistance of metals has a positive temperature coefficient of resistance, while the resistance of non-metals decreases with the increase of temperature, that is, it has a negative temperature coefficient.

The common feature of the atomic structure of metal elements is that the number of their outermost electrons (valence electrons) is small (generally only 1-2), and their binding force to the nucleus is weak, and it is easy to get rid of the bondage of the nucleus and become free electrons. When a large number of metal atoms are fused together to form a metal crystal, most of the metal atoms will lose their valence electrons and become positive ions, which are regularly arranged according to a certain geometric form and make high-frequency thermal vibrations in a fixed position. The valence electrons that are free from the bondage of atoms move freely between ions in the form of free electrons, which are common to the whole metal and form the so-called "electronic gas".

Metal crystals are combined by the mutual gravitational attraction between each positive ion and the common free electrons, and the repulsion between ions and ions and between electrons is balanced with this gravitational force, so that the metal is in a stable crystal state. This way the metal atoms are bonded is called a "metallic bond".

Since metal crystals are bonded by metallic bonds, metals have a series of metallic properties mentioned above. For example, free electrons in a metal will move in a directional direction along the direction of the electric field under the action of an external electric field, forming an electric current, thus showing good electrical conductivity.

In addition, because the positive ions in the metal are centered on a fixed position for thermal vibration, it has an obstructive effect on the flow of free electrons, which is the reason why the metal has resistance. With the increase of temperature, the amplitude of positive ion vibration increases, and the obstruction effect on the passage of free electrons also increases, so the resistance of the metal increases with the increase of temperature, that is, it has a positive temperature coefficient of resistance.

To sum up, it is not difficult for us to draw the following conclusions: the main reason why the resistivity of the metal increases with the increase of temperature is because of the obstruction of free electrons when the positive ions in the metal are subjected to thermal vibration, and the higher the temperature, the greater the amplitude of the positive ions, the stronger the hindrance effect, so the resistance of the metal will increase with the increase of temperature, which is the real reason why the voltammetry characteristic curve of the small bulb is not straight.

The flow of free electrons is hindered by thermally vibrating particles, so the resistance increases

A thermistor is a resistance that is very sensitive to temperature, and when the temperature changes slightly, its resistance chain dispersion value will change, which is the main characteristic of thermistor. Bump into the light.

According to the relationship between the resistance value and the temperature change, it can be divided into two categories: positive temperature coefficient thermistors and negative temperature coefficient thermistors.

The characteristic of a positive temperature coefficient thermistor is that the resistance value increases significantly as the temperature increases.

Negative temperature coefficient thermistors are characterized by the fact that the resistance value decreases as the temperature changes.

These two types of thermistors can be selected separately depending on the requirements.

Hello dear! Its resistance increases or decreases. Hope it helps, thank you!

As the resistance increases, the resistance value naturally increases.

The relationship between resistance and temperature is that the higher the temperature, the greater the resistance.

Resistance is a physical quantity that represents the magnitude of a conductor's resistance to an electric current in physics. The greater the resistance of the conductor, the greater the resistance of the conductor to the current. The resistance of different conductors is generally different, and resistance is a characteristic of the conductor itself.

The resistance will cause a change in the flow of electrons, and the smaller the resistance, the greater the flow of electrons, and vice versa. Superconductors, on the other hand, have no resistance to the Sakura pants.

The magnitude of the resistance value of the resistive element is generally related to the temperature, but also to the conductor length, cross-sectional ridge Kai product, and material. While the resistance of most metals increases with temperature, some semiconductors do the opposite.

Resistance Influencing Factors:

1. Length: When the material and cross-sectional area are the same, the longer the length of the conductor, the greater the resistance.

2. Cross-sectional area: When the material and length are the same, the smaller the cross-sectional area of the conductor, the greater the resistance.

3. Material: When the length and cross-sectional area are the same, the conductor resistance of different materials is different.

4. Temperature: For most conductors, the higher the temperature, the greater the resistance, such as metals. For a few conductors, the higher the temperature, the lower the resistance, such as carbon. <>

The resistance of most thermistors decreases with increasing temperature; There are also some that increase with increasing temperature, which is also the property of most conductors. Generally we take advantage of the properties of the former thermistor. For example, a temperature control circuit is designed by using the resistance value to decrease as the temperature increases.

When the temperature of the object increases, the resistance value in the circuit decreases, and the current in the circuit increases, and an alarm will be given when the current reaches the required limit current. There are also electronic thermometers. As the temperature of the human body increases, the circuit current in the electronic thermometer increases, and the corresponding indicator also increases.

RTD is the most commonly used temperature detector element in the middle and low temperature area RTD temperature measurement is based on the resistance of the metal conductor and the value increases with the increase of temperature

So the answer is: heat

The resistance of a thermistor with a positive temperature coefficient increases with increasing temperature, while the thermistor with a negative temperature coefficient decreases with increasing temperature.

Normally, the resistance also changes with temperature, usually increasing, but it is not as obvious as the thermistor, and the change is not regular.

Because the higher the temperature, the more intense and irregular the movement of electrons inside the object, because the current is formed by the directional movement of electrons, so when the irregular movement trend of electrons increases, it hinders the directional flow of electrons, resulting in fewer electrons directed through a cross-sectional plane per unit time, so the current becomes smaller, and the performance is increased by macroscopic resistance.

To put it more intuitively, to be precise, for a general linear resistance, there is the following formula:

0(1+ t), where represents the resistivity of the resistance, which is a physical characteristic quantity proportional to the resistance value, 0 is an initial value, is a constant, represents the temperature coefficient, and t represents the temperature we know it well. In general, a positive value is taken, so as the temperature increases, the resistance value also rises.

But of course, there are resistance changes that are not like this, such as thermistors (the resistance decreases with increasing temperature within a certain range).

Metals conduct electricity because of the presence of free electrons, and when the temperature is high, the irregular motion of free electrons accelerates, and it is more difficult to orient them.

The reason why a semiconductor has a conductivity between a conductor and an insulator is that its atomic structure is relatively special, that is, its outer electrons are neither as respectful as conductors can easily break free from the constraints of their nuclei, nor are they tightly bound by the nucleus like electrons in an insulator. This determines its conductivity to be somewhere in between. The higher the temperature, the easier it is for the outer electrons to break free from the shackles of their nuclei and become free electric large rocks, and the higher the conductivity of the rollers.

Wrong: The conductor is not necessarily the higher the comma scale, the greater the resistance, such as a pencil lead. The higher the temperature of an insulator such as glass, the lower the resistance. The resistance of semiconductors does not necessarily mean that the higher the temperature, the smaller the resistance, depending on the sum of the mixed substances, and you can change it as you like.