Question

determine the resistance of a copper wire having a length of 1 km and diameter of 0.5 mm

Answer 1

Well I think you should calculate yourselves npw

Answer 2

Hello!

• $\bf\small{ANSWER}$ :

$\boxed{\red{\sf 85\: \varOmega}}$

• $\bf\small{EXPLANATION}$ :

$\star \: \sf Length, L = 1000\:m \\ \star \: \sf Diameter, D = 0.50 mm \\ \\ \sf Then, \\ \\ \star \: \sf r = 0.25 \:mm = 0.25\times10^{-3} \:$
        
$\star$ $\sf Resistivity, \:p$ = $1.7 \times 10^{-8}$

Now,

$\bf\small{R}$ = $\dfrac{1.7 \times 10^{-8} \times 1000}{0.25\times 10^{-3}} = \boxed{\red{\sf 85\: \varOmega}}$

Cheers!