Consider a copper cylinder at room temperature. What happens to the resistivity of a copper cylinder as its temperature increases?

The correct answer is Increases.

Key Points

• Resistivity of metals, including copper, increases with an increase in temperature due to enhanced scattering of conduction electrons by vibrating atoms.
• This behavior is governed by the temperature dependence of electrical resistivity in metals, as described by the Drude model.
• Copper, being a good conductor, experiences a rise in resistivity as thermal agitation disrupts the orderly flow of electrons.
• The resistivity-temperature relationship for metals is nearly linear within the range of room temperature to moderate heating.
• The phenomenon can be expressed mathematically as: ρ(T) = ρ₀[1 + α(T - T₀)], where ρ₀ is the resistivity at reference temperature T₀, and α is the temperature coefficient of resistivity.

Additional Information

• Resistivity: It is the property of a material that quantifies how strongly it opposes the flow of electric current.
• Temperature Coefficient: It is a parameter that indicates how the resistivity of a material changes with temperature.
• Drude Model: A classical model explaining electrical conductivity in metals by treating conduction electrons as a gas that scatters due to collisions with atoms.
• Applications: The temperature dependence of resistivity is crucial in designing temperature sensors, such as resistance temperature detectors (RTDs).
• Exceptions: Unlike metals, semiconductors exhibit a decrease in resistivity with increasing temperature due to the availability of more charge carriers.