# A wire has a diameter of D=0.95 cm and is L=85 m long. When connected to a V=21 V source the wire...

## Question:

A wire has a diameter of {eq}D=0.95 cm {/eq} and is {eq}L=85 m {/eq} long. When connected to a {eq}V=21 V {/eq} source the wire passes a {eq}I=75 A {/eq} current. What is the resistivity of the wire?

## Resistivity And Resistance:

The resistance of a wire is determined by the dimensions of the wire and the resistivity of the material, {eq}\rho {/eq}. The resistance is

{eq}\displaystyle R = \rho \frac{L}{A}, {/eq}

where L is the length of the wire and A is its cross-sectional area.

The current, I, through a resistance can be found using Ohm's law:

{eq}\displaystyle I = \frac{V}{R}, {/eq}

where V is the potential difference applied across the resistance.

## Answer and Explanation: 1

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The total resistance, R, of the wire can be found using Ohm's law:

{eq}\displaystyle R = \frac{V}{I}, {/eq}

where V = 21 V is the potential...

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#### Learn more about this topic:

Electrical Resistance: Definition, Unit & Variables

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Chapter 6 / Lesson 8
23K

What is electrical resistance? Learn the meaning and formula of electrical resistance with examples. Understand the factors on which the resistance depends.