Mell What is electrical resistance of a material?
Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). Conductors: Materials that offer very little resistance where electrons can move easily.
How does material affect electrical resistance?
How much resistance a material has depends on several factors: the type of material, its width, its length, and its temperature. All materials have some resistance, but certain materials resist the flow of electric current more or less than other materials do. A longer wire has more resistance than a shorter wire.
What happens to the resistance R of a copper wire as its diameter decreases?
Resistance is inversely proportional to the Area of cross section of the wire. Doubling the radius increases the cross sectional area of the wire four times.
Why are some metals more resistant to electricity than others?
Impurities in metals cause electrical resistance by keeping the electrons from moving smoothly. Increases in temperature likewise slow down the flow of electrons by causing electrical resistance. Wires that are thinner or longer also provide more resistance to electricity than thicker or shorter wires.
What are the factors that affect electrical resistance?
The electrical resistance of a conductor is dependent on the following factors: The cross-sectional area of the conductor. Length of the conductor. The material of the conductor. The temperature of the conducting material.
What makes a material have a high or low resistivity?
A material with high resistivity means it has got high resistance and will resist the flow of electrons. A material with low resistivity means it has low resistance and thus the electrons flow smoothly through the material. For example, Copper and Aluminium have low resistivity.
What is the relationship between electrical conductivity and resistivity?
Electrical conductivity is the measure of how easily electricity flows through a material. Conductivity and resistivity are inversely proportional to each other. When conductivity is low, resistivity is high. When resistivity is low, conductivity is high.