What is resistivity of conductor in hindi

https://phys.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fphys.libretexts.org%2FBookshelves%2FUniversity_Physics%2FBook%253A_University_Physics_(OpenStax)%2FBook%253A_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)%2F09%253A_Current_and_Resistance%2F9.04%253A_Resistivity_and_Resistance \( \newcommand\) • • • • • • • • • • • • • • • • Learning Objectives By the end of this section, you will be able to: • Differentiate between resistance and resistivity • Define the term conductivity • Describe the electrical component known as a resistor • State the relationship between resistance of a resistor and its length, cross-sectional area, and resistivity • State the relationship between resistivity and temperature What drives current? We can think of various devices—such as batteries, generators, wall outlets, and so on—that are necessary to maintain a current. All such devices create a potential difference and are referred to as voltage sources. When a voltage source is connected to a conductor, it applies a potential difference V that creates an electrical field. The electrical field, in turn, exerts force on free charges, causing current. The amount of current depends not only on the magnitude of the voltage, but also on the characteristics of the material that the current is flowing through. The material can resist the flow of the charges, and the measure of how much a material resists the flow of charges is known as the resistivity. Thi...

Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity Silver 1.59×10 −8 6.30×10 7 Copper 1.68×10 −8 5.96×10 7 Annealed copper 1.72×10 −8 5.80×10 7 Gold 2.44×10 −8 4.10×10 7 Aluminum 2.82×10 −8 3.5×10 7 Calcium 3.36×10 −8 2.98×10 7 Tungsten 5.60×10 −8 1.79×10 7 Zinc 5.90×10 −8 1.69×10 7 Nickel 6.99×10 −8 1.43×10 7 Lithium 9.28×10 −8 1.08×10 7 Iron 1.0×10 −7 1.00×10 7 Platinum 1.06×10 −7 9.43×10 6 Tin 1.09×10 −7 9.17×10 6 Carbon steel (10 10) 1.43×10 −7 Lead 2.2×10 −7 4.55×10 6 Titanium 4.20×10 −7 2.38×10 6 Grain oriented electrical steel 4.60×10 −7 2.17×10 6 Manganin 4.82×10 −7 2.07×10 6 Constantan 4.9×10 −7 2.04×10 6 Stainless steel 6.9×10 −7 1.45×10 6 Mercury 9.8×10 −7 1.02×10 6 Nichrome 1.10×10 −6 9.09×10 5 GaAs 5×10 −7 to 10×10 −3 5×10 −8 to 10 3 Carbon (amorphous) 5×10 −4 to 8×10 −4 1.25 to 2×10 3 Carbon (graphite) 2.5×10 −6 to 5.0×10 −6 //basal plane 3.0×10 −3 ⊥basal plane 2 to 3×10 5 //basal plane 3.3×10 2 ⊥basal plane Carbon (diamond) 1×10 12 ~10 −13 Germanium 4.6×10 −1 2.17 Sea water 2×10 −1 4.8 Drinking water 2×10 1 to 2×10 3 5×10 −4 to 5×10 −2 Silicon 6.40×10 2 1.56×10 −3 Wood (damp) 1×10 3 to 4 10 −4 to 10 -3 Deionized water 1.8×10 5 5.5×10 −6 Glass 10×10 10 to 10×10 14 10 −11 to 10 −15 Hard rubber 1×10 13 10 −14 Wood (oven dry) 1×10 14 to 16 10 −16 to 10 -14 Sulfur 1×10 15 10 −16 Air 1.3×10 16 to 3.3×10 16 3×10 −15 to 8×10 −15 Paraffin wax 1×10 17 10 −18 Fused quartz 7.5×10 17 1.3×10 −18 PET 10×10 20 10 −21 Teflon 10×10 22 to 10×10 24 10 −25 to 10...

\( \newcommand\) • • • • • • Material and Shape Dependence of Resistance The resistance of an object depends on its shape and the material of which it is composed. The cylindrical resistor in Figure 1 is easy to analyze, and, by so doing, we can gain insight into the resistance of more complicated shapes. As you might expect, the cylinder’s electric resistance \(R\) is directly proportional to its length \(L\), similar to the resistance of a pipe to fluid flow. The longer the cylinder, the more collisions charges will make with its atoms. The greater the diameter of the cylinder, the more current it can carry (again similar to the flow of fluid through a pipe). In fact, \(R\) is inversely proportional to the cylinder’s cross-sectional area \(A\). Figure \(\PageIndex\) Example \(\PageIndexm\). Discussion The diameter is just under a tenth of a millimeter. It is quoted to only two digits, because ρ is known to only two digits. Temperature Variation of Resistance The resistivity of all materials depends on temperature. Some even become superconductors (zero resistivity) at very low temperatures. (See Figure 2.) Conversely, the resistivity of conductors increases with increasing temperature. Since the atoms vibrate more rapidly and over larger distances at higher temperatures, the electrons moving through a metal make more collisions, effectively making the resistivity higher. Over relatively small temperature changes (about \(100^\):These familiar thermometers are based on th...

More • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • The resistivity of a Conductor: • The resistivity of a conductor is defined as the resistance offered by the material per unit length for a unit cross-section . • It is denoted by the symbol ρ • The formula is ρ = R . A L, R is the resistance of the material, A is the area of cross-section and L is the length • The property of the material can be defined by resistivity and is dependent on pressure and temperature. • ρ = E J , E is the electric field and J is the current density. • The resistivity of conductors is low when compared to the resistivity of the insulators. • The unit of resistivity is Ohm-meter.

\( \newcommand\) • • • • • • Material and Shape Dependence of Resistance The resistance of an object depends on its shape and the material of which it is composed. The cylindrical resistor in Figure 1 is easy to analyze, and, by so doing, we can gain insight into the resistance of more complicated shapes. As you might expect, the cylinder’s electric resistance \(R\) is directly proportional to its length \(L\), similar to the resistance of a pipe to fluid flow. The longer the cylinder, the more collisions charges will make with its atoms. The greater the diameter of the cylinder, the more current it can carry (again similar to the flow of fluid through a pipe). In fact, \(R\) is inversely proportional to the cylinder’s cross-sectional area \(A\). Figure \(\PageIndex\) Example \(\PageIndexm\). Discussion The diameter is just under a tenth of a millimeter. It is quoted to only two digits, because ρ is known to only two digits. Temperature Variation of Resistance The resistivity of all materials depends on temperature. Some even become superconductors (zero resistivity) at very low temperatures. (See Figure 2.) Conversely, the resistivity of conductors increases with increasing temperature. Since the atoms vibrate more rapidly and over larger distances at higher temperatures, the electrons moving through a metal make more collisions, effectively making the resistivity higher. Over relatively small temperature changes (about \(100^\):These familiar thermometers are based on th...

Material ρ (Ω•m) at 20 °C Resistivity σ (S/m) at 20 °C Conductivity Silver 1.59×10 −8 6.30×10 7 Copper 1.68×10 −8 5.96×10 7 Annealed copper 1.72×10 −8 5.80×10 7 Gold 2.44×10 −8 4.10×10 7 Aluminum 2.82×10 −8 3.5×10 7 Calcium 3.36×10 −8 2.98×10 7 Tungsten 5.60×10 −8 1.79×10 7 Zinc 5.90×10 −8 1.69×10 7 Nickel 6.99×10 −8 1.43×10 7 Lithium 9.28×10 −8 1.08×10 7 Iron 1.0×10 −7 1.00×10 7 Platinum 1.06×10 −7 9.43×10 6 Tin 1.09×10 −7 9.17×10 6 Carbon steel (10 10) 1.43×10 −7 Lead 2.2×10 −7 4.55×10 6 Titanium 4.20×10 −7 2.38×10 6 Grain oriented electrical steel 4.60×10 −7 2.17×10 6 Manganin 4.82×10 −7 2.07×10 6 Constantan 4.9×10 −7 2.04×10 6 Stainless steel 6.9×10 −7 1.45×10 6 Mercury 9.8×10 −7 1.02×10 6 Nichrome 1.10×10 −6 9.09×10 5 GaAs 5×10 −7 to 10×10 −3 5×10 −8 to 10 3 Carbon (amorphous) 5×10 −4 to 8×10 −4 1.25 to 2×10 3 Carbon (graphite) 2.5×10 −6 to 5.0×10 −6 //basal plane 3.0×10 −3 ⊥basal plane 2 to 3×10 5 //basal plane 3.3×10 2 ⊥basal plane Carbon (diamond) 1×10 12 ~10 −13 Germanium 4.6×10 −1 2.17 Sea water 2×10 −1 4.8 Drinking water 2×10 1 to 2×10 3 5×10 −4 to 5×10 −2 Silicon 6.40×10 2 1.56×10 −3 Wood (damp) 1×10 3 to 4 10 −4 to 10 -3 Deionized water 1.8×10 5 5.5×10 −6 Glass 10×10 10 to 10×10 14 10 −11 to 10 −15 Hard rubber 1×10 13 10 −14 Wood (oven dry) 1×10 14 to 16 10 −16 to 10 -14 Sulfur 1×10 15 10 −16 Air 1.3×10 16 to 3.3×10 16 3×10 −15 to 8×10 −15 Paraffin wax 1×10 17 10 −18 Fused quartz 7.5×10 17 1.3×10 −18 PET 10×10 20 10 −21 Teflon 10×10 22 to 10×10 24 10 −25 to 10...

https://phys.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fphys.libretexts.org%2FBookshelves%2FUniversity_Physics%2FBook%253A_University_Physics_(OpenStax)%2FBook%253A_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)%2F09%253A_Current_and_Resistance%2F9.04%253A_Resistivity_and_Resistance \( \newcommand\) • • • • • • • • • • • • • • • • Learning Objectives By the end of this section, you will be able to: • Differentiate between resistance and resistivity • Define the term conductivity • Describe the electrical component known as a resistor • State the relationship between resistance of a resistor and its length, cross-sectional area, and resistivity • State the relationship between resistivity and temperature What drives current? We can think of various devices—such as batteries, generators, wall outlets, and so on—that are necessary to maintain a current. All such devices create a potential difference and are referred to as voltage sources. When a voltage source is connected to a conductor, it applies a potential difference V that creates an electrical field. The electrical field, in turn, exerts force on free charges, causing current. The amount of current depends not only on the magnitude of the voltage, but also on the characteristics of the material that the current is flowing through. The material can resist the flow of the charges, and the measure of how much a material resists the flow of charges is known as the resistivity. This...

More • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • The resistivity of a Conductor: • The resistivity of a conductor is defined as the resistance offered by the material per unit length for a unit cross-section . • It is denoted by the symbol ρ • The formula is ρ = R . A L, R is the resistance of the material, A is the area of cross-section and L is the length • The property of the material can be defined by resistivity and is dependent on pressure and temperature. • ρ = E J , E is the electric field and J is the current density. • The resistivity of conductors is low when compared to the resistivity of the insulators. • The unit of resistivity is Ohm-meter.