Question

Electrical resistance in a wire depends on the wire's __________.I. lengthII. diameterIII. resistivityGroup of answer choicesIIIAll of the aboveIIINone of the above

Answer 1

Electrical resistance is directly proportional to the length of the wire.

`R\propto length`

Electrical resistance is inversely proportional to the area of the cross section.

`\begin{gathered} \text{R }\propto\text{ Ar}ea \\ R\propto\pi(radius)^2 \\ R\propto diameter \end{gathered}`

Electrical resistance is directly proportional to the resistivity

`R\propto resistivity`

Thus, the correct option is all of the above.