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Well, there's typically two types of materials-Those with positive temperature coefficient and those with negative temperature coefficient.
Positive temperature coefficient are those whose resistance increases as temperature increases.
Negative temperature cofficient are those whose resistance decrease when the temperature increase.
There are however some alloys such as Manganin& Constantan whose resistance is not affected by temperature
What else can I help you with?
What is the significance of the constant temperature reference in ohms law?
As temperature affects resistivity, the resistance of a conductor may change if its temperature is allowed to increase. For pure metal conductors, the resistance generally increases as the temperature increases.Ohm's Law ('the current flowing along a conductor, at constant temperature, is directly proportional to the potential difference across that conductor') only applies when the resistance of the conductor is constant so, when verifying Ohm's Law, the temperature must be kept constant, in order to keep the resistance constant.It should be pointed out that the ratio of voltage (U) to current (R) is called resistance (R), and the resistance of a circuit can be found from the equation, R = U/I whether Ohm's Law applies or not -but Ohm's Law itself only applies when the ratio is constant over a range of voltage variation.
What is the resistance of SCR anode and Cathode?
The resistance of a Silicon Controlled Rectifier (SCR) anode and cathode is typically very low when the SCR is in the forward conducting state, allowing current to flow easily. In the reverse state, the resistance is very high, effectively blocking current flow. The exact resistance values can vary based on the specific SCR model and operating conditions, but the general principle remains the same: low resistance in the forward direction and high resistance in the reverse direction.
What is the electrical resistance of a penny?
The electrical resistance of a penny can vary based on its composition and condition, but a typical copper penny (post-1982) has a resistance of about 1 to 2 ohms. This value can change due to factors like oxidation, surface condition, and temperature. Generally, the resistance is low due to copper's excellent conductivity.
Is a Resistor a nonlinear device?
It is a linear device if it is not a wire wound resistor. These become non linear to AC at high frequencies because of their inherent inductance.
Does every different conducting substance have a unique resistivity?
Please note that resistivity also depends on temperature.In the most general case, the answer is definitely NO; all superconductors have the same resistivity, namely zero. Other than superconductors, take a look at a table with some typical resistivity values. It would seem quite obvious that for a given temperature: * Two different substances will, in general, have different resistivities. * In practice, in some cases the difference in resistivity might be too small to reliably measure. * It should be possible to find two substances that have the same resistivity at a very specific temperature - since the temperature-dependence will vary from one material to another. * Likewise, it should be possible to design a mix of two substances, which exactly matches that of another, given, substance.
Why is a filiament lamp a non ohmic conductor?
A filament lamp is a non-ohmic conductor because its resistance changes with applied voltage. As the voltage increases, the resistance also increases. This is due to the temperature-dependent behavior of the filament material, which causes the resistance to vary.
How does resistance of metal vary 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.
Graph of resistance of filament lamp against potential difference?
As potential difference increases in a filament lamp, resistance also increases due to an increase in temperature. The relationship between resistance and potential difference in a filament lamp is non-linear due to the temperature-dependent nature of resistance in the filament material. At low voltages, the resistance is relatively low, but as the temperature of the filament increases with higher voltages, the resistance also increases.
What is relation between voltage and temp?
The relationship between voltage and temperature can vary based on the material or device in question. In general, an increase in temperature can lead to an increase in resistance, which in turn can affect the voltage drop across a circuit. It is important to consider the specific characteristics of the material or device when analyzing the relationship between voltage and temperature.
What is the significance of the constant temperature reference in ohms law?
As temperature affects resistivity, the resistance of a conductor may change if its temperature is allowed to increase. For pure metal conductors, the resistance generally increases as the temperature increases.Ohm's Law ('the current flowing along a conductor, at constant temperature, is directly proportional to the potential difference across that conductor') only applies when the resistance of the conductor is constant so, when verifying Ohm's Law, the temperature must be kept constant, in order to keep the resistance constant.It should be pointed out that the ratio of voltage (U) to current (R) is called resistance (R), and the resistance of a circuit can be found from the equation, R = U/I whether Ohm's Law applies or not -but Ohm's Law itself only applies when the ratio is constant over a range of voltage variation.
What a relation between temperature and resistance?
Electricity is energy. Only matter can have temperature.
What combination of factors is most suitable for increasing the electrical conductivity of metals?
Resistivity is a constant for any particular material, and independent of that material's physical dimensions or shape. However, it does vary with temperature which is why resistivity is always quoted at a particular temperature. Variations in resistivity due to temperature change is the reason that the resistance of a material varies with temperature. In SI, resistivity is expressed in ohm metres.
What is temperature coefficient for insulator?
"Temperature coefficient" means, how does a certain physical quantity vary, depending on the temperature. In this case, the physical quantity in question is probably the electrical resistance, or the electrical resistivity.
How does resistance vary with the length of a conductor?
Resistance in a conductor increases as the length of the conductor increases. This is because a longer conductor provides more material for electrons to collide with, resulting in more resistance to the flow of electric current.
What type of material is Bakelite isotropic or nonisotropic?
Bakelite is considered a nonisotropic material. This means that its properties, such as thermal conductivity or electrical resistance, can vary depending on the direction in which they are measured within the material.
What temperature is required to start a fire?
A fire typically starts when a material reaches its ignition temperature, which can vary depending on the material. In general, most materials ignite at temperatures between 500 to 600 degrees Fahrenheit.
What are the three physical properties that vary with temperature?
Three physical properties that vary with temperature are volume, density, and thermal expansion coefficient. As temperature increases, volume generally expands, which can lead to a decrease in density. The thermal expansion coefficient quantifies how much a material expands or contracts with changes in temperature.
