In this problem, we're looking for the potential drop, V across the cable given by Ohm's law:

$\overline{){\mathbf{V}}{\mathbf{=}}{\mathbf{i}}{\mathbf{R}}}$

and electrical energy, E dissipated as thermal energy per hour given by:

$\overline{){\mathbf{E}}{\mathbf{=}}{\mathbf{P}}{\mathbf{\times}}{\mathbf{T}}}$, where P is the power and T is the time in seconds.

A copper transmission cable 100 km long and 10.0 cm in diameter carries a current of 125 A.

(a) What is the potential drop across the cable?

(b) How much electrical energy is dissipated as thermal energy every hour?

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Resistors and Ohm's Law concept. You can view video lessons to learn Resistors and Ohm's Law. Or if you need more Resistors and Ohm's Law practice, you can also practice Resistors and Ohm's Law practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Blake's class at Oxford College of Emory University.