Explanation:
It is given that,
Diameter of the copper wire, d = 2.3 cm
Radius of copper wire, r = 1.15 cm = 0.0115 m
Distance between bird's feet, l = 3.9 cm = 0.039 m
The resistivity of the wire, [tex]\rho=1.7\times 10^{-8}\ \Omega-m[/tex]
We need to find the potential difference between bird's feet. The resistance of the wire is calculated by :
[tex]R=\rho\times \dfrac{l}{A}[/tex]
[tex]R=1.7\times 10^{-8}\ \Omega-m\times \dfrac{0.039\ m}{\pi(0.0115\ m)^2}[/tex]
R = 0.00000159 ohms
[tex]R=1.59\times 10^{-6}\ \Omega[/tex]
Let V is the potential difference between bird's feet. It can be calculated using Ohm's law as :
[tex]V=I\times R[/tex]
[tex]V=45\ A\times 1.59\times 10^{-6}\ \Omega[/tex]
V = 0.000071 volts
or
[tex]V=7.1\times 10^{-5}\ volts[/tex]
So, the potential difference between the bird's feet is [tex]7.1\times 10^{-5}\ volts[/tex]. Hence, this is the required solution.
