A 1.0-mm diameter extension cord is made of metal having a resistivity of 1.68 × 10^-8 Ω ∙ m.When it carries a current of 15 A,what is the potential difference between two points in the cord that are 100 m apart? A)12 V B)23 V C)32 V D)41 V

Question

Quizplus · Accepted Answer

First, we need to calculate the resistance of the extension cord using the formula:

R = (ρ x L)/A

where R is the resistance, ρ is the resistivity, L is the length, and A is the cross-sectional area.

We know the diameter of the cord (1.0 mm) and can use this to find the cross-sectional area:

A = π x (d/2)² = 0.785 mm² = 7.85 x 10^-7 m²

Next, we can calculate the resistance:

R = (1.68 x 10^-8 Ω∙m x 100 m) / (7.85 x 10^-7 m²) = 2.15 Ω

Now we can use Ohm's law to find the potential difference (V) across the cord:

V = IR

V = (15 A) x (2.15 Ω) = 32.25 V

Therefore, the potential difference between two points in the cord that are 100 m apart is 32 V, which is closest to choice C.

A 10-Mm Diameter Extension Cord Is Made of Metal Having a a Resistivity