What is the resistance of a metallic conductor?
Resistance of a metallic conductor increases with the increase (or rise) in temperature, because the temperature coefficient of conductors is positive in nature hence resistance is directly proportional to the temperature.
What is resistivity of a conductor?
The resistivity of a conductor is defined as the resistance offered by the material per unit length for unit cross-section. Resistivity is a property of the material and depends on temperature and pressure. The resistivity of conductors is low when compared to the resistivity of the insulators.
How do you find the resistance of a metallic conductor?
As the length of wire increases, the resistance will increase. The greater the length of wire the greater the number of collisions between the free electrons and metal ions. This will result in greater resistance.
What is resistivity of a metal?
Resistivity is the resistance per unit length and cross-sectional area. It is the property of the material that opposes the flow of charge or the flow of electric current. ρ = R A / L, where R is the resistance in ohms, A is the area of cross-section in square meters and L is the length in meters. …
How does the resistivity of metallic conductor depends on temperature?
The resistivity of conductors increases with rise in temperature. As the temperature of the conductor increases, the average speed of the electrons acting as the current carriers increases. Since the resistivity is inversely proportional to the average time , therefore resistivity increases.
Is conductivity and resistivity the same?
Conductivity vs Resistivity Since conductivity is the measure of how easily electricity flows, electrical resistivity measures how much a material resists the flow of electricity.
How do you find the resistance of a conductor?
Specific Resistance (”ρ”) is a property of any conductive material, a figure used to determine the end-to-end resistance of a conductor given length and area in this formula: R = ρl/A. Specific resistance for materials are given in units of Ω-cmil/ft or Ω-meters (metric).
At which temperature the resistivity of metallic conductor becomes zero?
absolute zero
Resistivity in a metal is a function of temperature; it increases with temperature due primarily to electron-phonon interaction. However, due to the presence of small amount of impurities and defects, the resistivity is finite even at absolute zero. Thus both resistivity and conductivity are finite at absolute zero.
Why do metals have low resistivity?
Answer:Conductors have number of free electrons in them hence they have low resistance. As number of electrons increases resistance of the matter decreases because number of electrons will decide flow of current or heat through it.
Which conductor has highest resistivity?
The unit for resistivity is the ohm-meter. Materials that conduct electrical current easily are called conductors and have a low resistivity. Materials that do not conduct electricity easily are called insulators and these materials have a high resistivity….Detailed Solution.
| Metal | Resistivity |
|---|---|
| Mercury | 9.80×10−7 |
How are resistivity and conductivity of a material related?
Resistivity, also referred to as specific resistance, is dependent on the nature of the material as well as its volume definition (shape and size). Resistivity is expressed in units that are the product of resistance and length; e.g., Ω·cm. The symbol most commonly used for resistivity is rho ( ρ ). Conductivity is the reciprocal of resistivity.
How is the resistivity of a wire calculated?
The units of resistivity are ohm-meters. The resistance of a wire or rod of uniform cross section can be calculated as (resistivity) * (length) Resistance = ———————— (cross section area) The resistivity of a material depends on its temperature. Most metals have lower resistance as the temperature drops.
When does the resistance of a metal decrease?
Most metals have lower resistance as the temperature drops. Some materials become superconductors when they fall below a critical temperature. They offer zero resistance to the flow of current. Viewgraph 2
Which is a factor in the table of resistivities?
Table of resistivities The factor in the resistance which takes into account the nature of the material is the resistivity. Although it is temperature dependent, it can be used at a given temperature to calculate the resistance of a wire of given geometry.