Question

Compared to the resistivity of a 0.4-meter length of 1-millimeter-diameter copper wire at 0 degrees Celsius, the resistivity of a 0.8-meter length of 1-millimeter-diameter copper wire at 0 degrees Celsius is: *

Answer 1

Answer:

c) the same

Explanation:

Answer 2

Answer:

Resistivity of both wires are same

Explanation:

Length of one wire,$l_1=0.4 m$

Diameter,$d_1=1mm$

Radius,$r_1=\frac{d_1}{2}=\frac{1}{2}mm=0.5\times 10^{-3} m$

$1mm=10^{-3} m$

$l_2=0.8 m$

$d_2=1mm$

$r_2=0.5\times 10^{-3} m$

Temperature in each case is same.

Area of each wire,$A_1=A_2=A=\pi r^2=\pi (0.5\times 10^{-3})^2m^2$

Resistivity is the property of material due to which it offers resistance to the flow of current.

Resistivity of material depends upon the temperature and material by which it is made.

It does not depends upon the length of object.

Therefore, the resistivity of both wires of different length  are same.