Answer:
[tex]R=5.12\ \Omega[/tex]
Explanation:
Electric Resistance and Temperature
For some materials, resistivity is linearly related to the temperature. The function that relates them is
[tex]R=R_o[1+\alpha (T-T_o)][/tex]
Where Ro is the electric resistance at 20°C, [tex]\alpha[/tex] is the temperature coefficient of the conductor, T is the actual temperature at which we want to compute R, and To is the initial temperature, usually 20°C.
The problem gives us the following values
[tex]R_o=5\ \Omega,\ T_o=20^oC,\ \alpha=0.0004\ ^oC^{-1},\ T=80^oC[/tex]
Thus
[tex]R=5[1+0.0004 (80-20)]=5.12\ \Omega[/tex]
[tex]\boxed{R=5.12\ \Omega}[/tex]
