TP 21.12

Given: I = 32.0 A

A = 0.130 cm²

l = 6.00 cm

r = 1.68 x 10^-8 W-m

(a) Find: DV - ?

Ohm's Law:

DV = I R

R = r l /A = (1.68 x 10^-8 W-m)(0.0600 m)/(0.130 cm²) = 0.775 x 10^-8 W

DV = (32.0 A) (0.775 x 10^-8 W) = 24.8 x 10^-8 V

(b) As the separation increases, so does the resistance of the wire between the bird’s feet, and so does the potential difference.