Question

Consider two copper wires with the same cross-sectional area. Wire A is twice as long as wire B. How do the resistivities and resistances of the two wires compare? Check all that apply. Check all that apply. Wire A and wire B have the same resistance. Wire A has twice the resistance of wire B. Wire A and wire B have the same resistivity. Wire B has twice the resistivity of wire A. Wire B has twice the resistance of wire A. Wire A has twice the resistivity of wire B. SubmitPrevious AnswersRequest Answer Incorrect; Try Again; 4 attempts remaining Your answer indicates that you need to review resistivity and resistance. Provide Feedback Next Incorrect. Incorrect; Try Again; 4 attempts remaining. Feedback. Your answer indicates that you need to review resistivity and resistance. End of feedback. g

Answer 1

Wire A has twice the resistance of wire B.

Wire A and wire B have the same resistivity.

Step-by-step explanation:

- Resistivity is a property of a material, that tells how much is the material able to oppose to the flow of current through it. The value of the resistivity of a wire depends on the material only: this means that two wires made of the same material have same resistivity. Since both wire A and B here are made of copper, they have the same resistivity.

- Resistance of a wire instead is given by

`R=\rho (L)/(A)`

where

`\rho` is the resistivity of the material

L is the length of the wire

A is the cross-sectional area of the wire

Here, the two wires have same resistivity and same cross-sectional area, while wire A is twice as long as wire B (so, L for A is twice the value of L for B): therefore, the resistance of wire A will be twice that of wire B.