0
Resistance is a property of a resistor, a circuit device with a "port" of 2 connections. Resistance is ratio of voltage across port/current looped through it; this is constant for most resistors.
Resistivity is a bulk property of a material, ratio of voltage/distance to current/area through a solid. Typically a constant.
Answer
Resistance is the opposition a material offers to the drift of current through that material, and is expressed in ohms. Resistance is directly-proportional to the resistivity of the material and to its length, and inversely-proportional to its cross-sectional area.
Resistivity, on the other hand, is the property a material has which makes different materials, of identical physical dimensions, have different values of resistance. It is defined as 'the resistance of a unit length of a material of uniform cross-sectional area'. In SI, this equates to the resistance between the opposite faces of a metre cube (NOT cubic metre -they're different!) of a material, and is expressed in ohm metres. Resistivity is affected by temperature, so it is always quoted at a specific temperature, usually 20 degrees Celsius.
Resistivity allows us to compare the resistance of different materials without taking their physical dimensions into account.
What else can I help you with?
Are all resistances in series connections the same?
No, all resistances in series connections are not the same. Different value resistances can be series together. The results of the resistances in series are always the same, they are additive.
What are the formulae of resistivity?
There is no 'formula' for resistivity. The resistivities of different conductors have been determined by experiment.
How can you measure resistivity from a graph?
Take measurements of resistances of various lengths of a wire of constant diameter. Make a graph of resistance against length / cross-sectional area of wire. The gradient of the straight line section will be equal to the resistivity of the wire.
What is the difference between metal and semiconductor?
A semiconductor's resistivity decreases with increasing temperature. A metal's resistivity increases with increasing temperature.
Why do the values of resistivity differ so much between materials?
The values of resistivity differ between materials due to variations in their atomic structure, electron configuration, and bonding characteristics. Materials with more free electrons, such as metals, have lower resistivity, while insulating materials with tightly bound electrons have higher resistivity. The presence of impurities and defects in a material can also influence its resistivity.
What is the resistivity of nichrome?
There are different compositions of nichrome, with different proportions of nickel and chromium. Resistivity of the various alloys ranges between 1.0 x 10-6 to 1.5 x 10-6 ohm-meter.
How are materials classified on the basis of resistivity?
Materials can be classified based on their resistivity as conductors, semiconductors, or insulators. Conductors have low resistivity, allowing electric current to flow easily. Semiconductors have resistivity in between conductors and insulators, and their conductivity can be controlled. Insulators have high resistivity and do not allow electric current to flow easily.
Difference between resistance and resistivity?
Nothing. Resistivity is defined as specific resistance. However, Resistivity is different from resistance.Answer:Resistance is the opposition offered by the material which is of any shape and size whereas resistivity is the resistance offered by the material with unit area of cross section and unit length.Therefore, resistance varies depending upon shape and size of the material while resistivity is constant for a particular material.
What is the factor affecting the resistivity?
The factors affecting resistivity include the material's composition, temperature, and impurities present. Different materials have different resistivities due to variations in electron mobility and collisions with lattice vibrations. Temperature affects resistivity because it changes the lattice vibrations and electron collisions within the material. Impurities can also increase resistivity by disrupting the flow of electrons.
How are substances classified on the basis of resistivity?
Substances are classified based on their resistivity as conductors, insulators, or semiconductors. Conductors have low resistivity and easily allow the flow of electric current. Insulators have high resistivity and inhibit the flow of electric current. Semiconductors have resistivity values between conductors and insulators, making them suitable for controlling the flow of current in electronic devices.
What is the relationship between resistivity and circumference?
The relationship between resistivity and circumference is inverse.The resistance of a substance decreases as the surface area of that substance increases. The greater circumference presents a greater conduction surface.AnswerThe original answer describes resistance, NOT resistivity. Additionally, it is incorrect because resistance is inversely-proportional to cross-sectional area NOT circumference!There is NO relationship between resistivity and the circumference of a material. Resisitivity is a constant at any given temperature and is completely unaffected by the dimensions of a material.
Why 4 probe is used instead of 2 probe to find the resistivity?
The four-probe method is used to measure resistivity because it eliminates the effects of contact resistance and lead resistance that can distort measurements in the two-probe method. In the four-probe setup, two probes are used to source current while the other two measure the voltage drop, ensuring that voltage measurements are not influenced by the resistances of the probes and contacts. This results in more accurate and reliable measurements of the material's intrinsic resistivity.
