The resistivity of iron is `1 xx 10^(-7)` ohm -m. The resistance of a iron wire of particular length and thickness is 1 ohm. If the length and the diameter of wire both are doubled, then the resistivity in ohm-m will be

Options

A. `1 xx 10^(-7)`
B. `2 xx 10^(-7)`
C. `4 xx 10^(-7)`
D. `8 xx 10^(-7)`

Answer

A

Explanation

(a) Resistivity of some material is its intrinsic porterty and is constant at particular temperature. Resistivity does not depend upon shape.