What is resistivity in simple words? Resistivity is a measure of the resistance of a given size of a specific material to electrical conduction. … Materials that conduct electrical current easily are called conductors and have a low resistivity. Those that do not conduct electricity easily are called insulators and these materials have a high resistivity.
What is resistivity in simple terms?
Resistivity, electrical resistance of a conductor of unit cross-sectional area and unit length. A characteristic property of each material, resistivity is useful in comparing various materials on the basis of their ability to conduct electric currents. High resistivity designates poor conductors.
What is the difference between resistivity and resistance?
Resistance is defined as the property of the conductor which opposes the flow of electric current. … Resistivity is defined as the resistance offered by the material per unit length for unit cross-section. The SI unit of resistivity is Ohm.
Does resistivity depend on length?
The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size.
Is specific resistance and resistivity same?
The specific resistance of a material is the resistance offered per unit length & per unit cross-sectional area. It is a constant value & it is equal to the resistivity of the material. It is measured in Ohms.
What’s the difference between resistivity and resistance?
Resistance is defined as the property of the conductor which opposes the flow of electric current. … Resistivity is defined as the resistance offered by the material per unit length for unit cross-section. The SI unit of resistivity is Ohm. meter.
What is the relation between resistivity and resistance?
For a conductor material, the resistance of the material is inversely proportional to the area of cross-section and directly proportional to the length of the conductor. Relation between Resistivity and Resistance is: R=ρlA, where ρ is the resistivity, l is the length of the conductor and A is the cross sectional area.
Is resistivity directly proportional to resistance?
Resistivity ρ is an intrinsic property of a material and directly proportional to the total resistance R, an extrinsic quantity that depends on the length and cross-sectional area of a resistor. The resistivity of different materials varies by an enormous amount.
What are the factors affecting resistivity?
Factors Effecting the Resistivity of Electrical Materials
- Temperature.
- Alloying.
- Mechanical stressing.
- Age Hardening.
- Cold Working.
Does resistivity affect resistance?
Resistance depends on the resistivity. The resistivity is a characteristic of the material used to fabricate a wire or other electrical component, whereas the resistance is a characteristic of the wire or component.
Does resistivity depend on temperature?
Resistivity depends on the temperature of the material. At a constant temperature, we can assume the resistivity is a constant, and use Ohm’s Law which states that the resistance will be constant.
Is resistivity directly proportional to temperature?
Resistivity is indirectly proportional to the temperature. In other words, as you increase the temperature of materials, their resistivities will decrease. But this is not true for every material i.e., all materials do not have the same dependence on temperature.
How does resistivity depend on area?
Resistance is inversely proportional to area of cross section. larger will be the area lower will be the resistance and vice versa. this is because through a conductor with large area of cross section current can easily flow and hence resistance is low.
What is called specific resistance?
Specific resistance is defined as the resistance offered per unit length and unit cross-sectional area when a known amount of voltage is applied. The mathematical representation is as follows: ρ=RAL.
What are the factors affecting resistance?
There are 4 different factors which affect resistance:
- The type of material of which the resistor is made.
- The length of the resistor.
- The thickness of the resistor.
- The temperature of the conductor.
What is the relation between temperature and resistance?
As temperature rises, the number of phonons increases and with it the likelihood that the electrons and phonons will collide. Thus when temperature goes up, resistance goes up. For some materials, resistivity is a linear function of temperature. The resistivity of a conductor increases with temperature.
Why is resistivity directly proportional to resistance?
Yes, for any object increase in resistivity will increase the resistance. Resistance is the opposition to the flow of charges in a conductor. Resistance depends on the length and area of the conductor. … Therefore, resistivity is equal to the resistance of the conductor with a unit cross-sectional area and unit length.
Which is directly proportional to the resistance?
The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area. Resistance also depends on the material of the conductor. … The resistance of a conductor, or circuit element, generally increases with increasing temperature.
What are the 4 factors of resistance?
There are 4 different factors which affect resistance:
- The type of material of which the resistor is made.
- The length of the resistor.
- The thickness of the resistor.
- The temperature of the conductor.
What affects resistivity of a wire?
The electrical resistance of a wire or circuit is a way of measuring the resistance to the flow of an electrical current. … The resistance of a given piece of wire depends of three factors: the length of the wire, the cross-sectional area of the wire, and the resistivity of the material composing the wire.
What are 4 factors affecting resistance in a wire?
There are several factors that affect the resistance of a conductor;
- material, eg copper, has lower resistance than steel.
- length – longer wires have greater resistance.
- thickness – smaller diameter wires have greater resistance.
- temperature – heating a wire increases its resistance.
What is current resistivity and resistance?
Current is the change in charge over the change in time. R = ρ l A R =dfrac{rho l}{A} R=Aρl. R R R is resistance, ρ is resistivity, l is length, and A is cross sectional area.
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 } |
Why does resistivity decrease with temperature?
When the temperature in increased the forbidden gap between the two bands becomes very less and the electrons move from the valence band to the conduction band. … Thus when the temperature is increased in a semiconductor, the density of the charge carriers also increases and the resistivity decreases.
Why does resistivity change with 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.
References
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