Describe what will happen to the resistance offered by a conductor given the following changes in its properties

Describe what will happen to the resistance offered by a conductor given the following changes in its properties: Increase in electrical resistivity Decrease in electrica conductivity Decrease in temperature Increase in length Fattening II. Describe what will happen to the current flow through a conductor given the following changes in its properties: Decrease in electrical resistivity Increase in electrical conductivity Increase in temperature Decrease in length Thinning

The Correct Answer and Explanation is:¹

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Changes Affecting the Resistance of a Conductor

1. Increase in electrical resistivity: Electrical resistivity is a material property that measures how strongly a material opposes the flow of electric current. When the resistivity of a conductor increases, its resistance will also increase. This is because the material will resist the flow of electrons more, leading to greater opposition to current flow.
2. Decrease in electrical conductivity: Electrical conductivity is the inverse of resistivity. When the conductivity decreases, it implies that the material is less effective at allowing the flow of electric current. Therefore, a decrease in conductivity results in an increase in resistance.
3. Decrease in temperature: Resistance typically decreases with a decrease in temperature for most conductors. This is because at lower temperatures, the atoms in the material vibrate less, which allows electrons to flow more freely, reducing the opposition to the current.
4. Increase in length: The resistance of a conductor is directly proportional to its length. When the length of a conductor increases, its resistance also increases because electrons have to travel through a longer path, encountering more collisions, thus hindering the flow of current more.
5. Fattening (Increase in cross-sectional area): The resistance of a conductor is inversely proportional to its cross-sectional area. When the conductor becomes thicker (or fattens), the resistance decreases because there is more space for the electrons to flow through, reducing the number of collisions between electrons and atoms.

Changes Affecting the Current Flow Through a Conductor

1. Decrease in electrical resistivity: A decrease in resistivity means the material offers less opposition to the flow of current. This leads to an increase in current flow, as the electrons can move more freely through the conductor.
2. Increase in electrical conductivity: Since electrical conductivity is the reciprocal of resistivity, an increase in conductivity means a decrease in resistance. As a result, current flow will increase because less energy is required to move electrons through the conductor.
3. Increase in temperature: Typically, for most conductors, an increase in temperature causes an increase in resistance. The atoms in the material vibrate more at higher temperatures, leading to more collisions with electrons, thus increasing resistance and reducing current flow.
4. Decrease in length: The current flowing through a conductor is inversely proportional to its length. When the length decreases, there is less resistance, and the current will increase because electrons face fewer collisions as they travel through the conductor.
5. Thinning (Decrease in cross-sectional area): When the conductor thins, its cross-sectional area decreases, which increases resistance. This higher resistance reduces the current flow, as the path for electrons to move through becomes narrower, causing more collisions.

Conclusion

Changes in a conductor’s properties significantly influence both its resistance and the current flow through it. Increasing resistivity, length, or temperature generally increases resistance, while decreasing resistivity, length, or increasing the cross-sectional area tends to increase current flow. Conductivity follows the inverse relationship with resistivity, and these relationships are crucial in understanding electrical circuits.