In a wire, electrons are moving close to the speed of light, but they normally collide with the crystal lattice atoms and scatter (no fixed directions; can be deflected forward or backward or sideways). Adding an electric field to the wire (applying the ends of the wire to the terminals of a battery), we can nudge the electrons to have a net movement (an electron moving 10 steps forward but nine steps back has a net movement of one step forward) in one direction (the battery is supplying a DC current). When one electron leaves the wire (at the positive terminal of the battery), another electron has to enter the wire from the negative terminal to maintain electrical neutrality of the wire almost instantly. Hence the flow of information is still near the speed of light. Resistance is the measure of how quick is the net movement of electrons -- the slowly the net movement, the higher the resistance. A higher temperature makes the electrons (like going nowhere faster) and the lattice atoms (more vibration) more excited than a lower temperature. The extra atomic vibration makes the electron transition across a wire more difficult, although the electrons have sped up.
An analogy is filling a room with two exits, one to the right and the other to the left, with people standing. These people are ordered to give a push of any approaching person in a random direction (unpredictable). The room is situated on a level ground. You enter from the right by accident. You start bumping into the people in the room. Each person you approach gives you a push in a totally random direction. You may get out the exit to the right or move to the wall to the far end -- totally random. Note that no matter how fast you run, you feel you are not going anywhere in particular. Adding an electric field is like the room is being tilted so that the right-hand exit is higher than the left-hand exit. You have a net movement going to the left because of the aid of gravitational pull. A higher temperature means you run at a faster speed and the other people in the room are shaking randomly too. The resulting chaos slow your net movement to the left.
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The thermistors are resistors whose resistance changes with the temperature. While for most of the metals the resistance increases with temperature, the thermistors respond negatively to the temperature and their resistance decreases with the increase in temperature. Since the resistance of thermistors is dependent on the temperature, they can be connected in the electrical circuit to measure the temperature of the body.
Resistance increases as temperature increases. If Voltage is held constant then according to Ohm's Law Voltage = Current x Resistance then current would decrease as resistance increases.
If temperature increases the resistance will also increase. This is why a light bulb is a non ohmic conductor. As the light bulb filament gets hotter its resistance will increase.Additional CommentsIt depends upon the material involved. In general, for pure metal conductors an increase in temperature will cause their resistance to increase. For insulators, an increase in temperature will cause their resistance to decrease -which is why excessive temperature is often the main reason why insulation fails. Alloys can be manufactured that will maintain a relatively constant resistance over a wide range of temperatures.Temperature affects resistance indirectly. What is actually being affected is the material's resistivity. Resistivity is one of the factors that determines resistance.The resistance of any given material can be calculated over wide range of temperatures, using the temperature coefficient of resistance for that material.
I assume you meant pressure to voltage. The resistance of a conductor is directly proportional to the temperature of the conductor. If the temperature of the conductor increases due to increased current, then the resistance tend to increase too.
In general, pure metal conductors increase in resistance as their temperature increases. This is not necessarily true for alloys, as some alloys are manufactured to have an approximately constant resistance over a wide range of temperatures.
The thermistors are resistors whose resistance changes with the temperature. While for most of the metals the resistance increases with temperature, the thermistors respond negatively to the temperature and their resistance decreases with the increase in temperature. Since the resistance of thermistors is dependent on the temperature, they can be connected in the electrical circuit to measure the temperature of the body.
most metals resistance increases with temperature
The resistance of metals generally increases with temperature due to increased atomic vibrations that impede the flow of electrons. This relationship is described by the temperature coefficient of resistance, which varies for different metals.
with increase temperature in metal, thermal energy causes atoms in metal to vibrate, in this excited state atoms interact with and scatter electrons, thus decreasing the mean free path, and hence the mobility of electrons to decreases and resistivity increase(Resistivity = 1 / Conductivity )so conductivity of metal decrease as increasing in temperature
Semiconductors: When temperature increases, more electrons jump to conduction band from valance bond. Hence resistance decreases. Metals: Already plenty of electrons are there in conduction band. When temperature increases, the electrons in conduction band of metal vibrate and collide each other during their journey. Hence the the resistance of metal increases with increase of temperature. S.Lakshminarayana
Negative temperature coefficient of resistance means that as the temperature of a piece of wire or a strip of semiconducting material increases, the electrical resistance of that material decreases.
In a wire, as the temperature increases, the atoms in the wire vibrate more rapidly, which causes more collisions with the flow of electrons, increasing resistance. However, in some materials like metals, as temperature rises, the atoms also move farther apart, which can offset the increase in collisions, leading to a net decrease in resistance. This is known as the positive temperature coefficient of resistance.
An increase in current will only affect resistance if it causes the temperature of the conductor to change. For pure metallic conductors, and increase in temperature will cause an increase in resistance.
It depends. In general, pure metal conductors increase in resistance as their temperature increases; some alloys (e.g. constantan) are manufactured to maintain an approximately-constant resistance for changes in temperature. Materials such as carbon (and most insulators) exhibit a fall in resistance as their temperatures increase.
Some materials with a positive temperature coefficient of resistance include silicon, germanium, and thermistors made of certain metal oxides like manganese, cobalt, and copper. These materials exhibit an increase in resistance with an increase in temperature, making them useful in temperature-sensing applications.
The slope of a resistance vs. temperature curve gives the temperature coefficient of resistance, which quantifies how much the resistance of a material changes with temperature. Positive values indicate the resistance increases with temperature (e.g., in most metals), while negative values indicate the resistance decreases with temperature (e.g., in semiconductors).
The resistance of pure metallic conductors increases with temperature, because the resistivity of these conductors increase with temperature.