Question

Resistivity of a given copper wire of length 2m is
1.7 x10^-8 ohm m. The wire is stretched so that its length
becomes 4m. Find new resistivity of the copper wire.
​

Answer 1

Given:

Resistivity of a copper wire of length 2m is 1.7 × 10^8 ohm m.

The wire is stretched such that its length becomes 4 m.

To find:

New resistivity of the copper wire.

Concept:

Resistivity of any wire is a materialistic property. This means that , resistivity shell depend only upon nature of material present in the wire. Resistivity will not depend upon the dimensions of the wire.

Hence , even after stretching of the wire the new resistivity of the copper wire will remain same and be equal to 1.7 × 10^8 ohm m.

Since resistivity is a constant value , the length of the wire and the cross sectional area will be inversely proportional to one another.

So , final answer is :

$\boxed{ \sf{new \: resistivity = 1.7 \times {10}^{8} \: ohm \:m}}$

Answer 2

Explanation:

resistivity of a material is a characteristic property which means that the resistivity will change only by changing the material.

changing the length or any other property will not change the resistivity

both the resistance and resistivity of a material vary with temperature.