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What is the resistivity (╧Б) of a material?
The resistance of a material of unit length and unit cross-sectional area.
The total resistance of a conductor.
The ability of a material to conduct electric current.
The reciprocal of the conductivity of a material.
The reciprocal of the conductivity of a material.
Resistivity (or specific electrical resistance) is an intrinsic material property that quantifies how strongly a material opposes the flow of electric current. Unlike resistance, which depends on the physical dimensions of the conductor, resistivity is a constant for a given material at a specific temperature.
Resistivity (or specific electrical resistance) is an intrinsic material property that quantifies how strongly a material opposes the flow of electric current. Unlike resistance, which depends on the physical dimensions of the conductor, resistivity is a constant for a given material at a specific temperature.
Think of resistivity as the 'narrowness' or 'roughness' of a pipe; a material with high resistivity is like a pipe filled with gravel, making it very difficult for water (current) to pass through, regardless of how short or wide the pipe is.
R=╧БALтАЛ тАФ Relation between resistance (R), resistivity (╧Б), length (L), and area (A)
╧Б=LRтЛЕAтАЛ тАФ Definition of resistivity in terms of measured physical parameters
When an electric field is applied to a conductor, free electrons collide with atoms/ions in the crystal lattice. These collisions hinder the flow of charge carriers, creating electrical resistance. Resistivity (╧Б) relates this macroscopic resistance (R) to the conductor's geometry via the formula R=╧БALтАЛ, where L is length and A is cross-sectional area.
Resistivity is an intrinsic property and does not change with the shape or size of the object.
The SI unit of resistivity is the ohm-meter (╬йтЛЕm).
It is strongly dependent on temperature (increases for metals with rising temperature).
Conductivity is the reciprocal of resistivity (╧Г=╧Б1тАЛ).
Used to identify materials for specific electrical applications (e.g., copper for wiring, nichrome for heaters).
Selection of materials for resistors and heating elements.
Designing electromagnetic shielding and electrical grounding systems.
Option A is incorrect because V├ЧI represents Power (P).
Option B is incorrect because current capacity depends on cross-sectional area and thermal limits.
Option C is incorrect because resistance is an extensive property, while resistivity is an intensive (intrinsic) property.
D is correct тАФ Resistivity is a measure of how strongly a material opposes the flow of electric current as an intrinsic property.
Remember that resistance depends on geometry (L and A), but resistivity depends only on the material type and temperature.
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