Question

The electrical resistance, r ohms, of 1,000 ft of solid copper wire at 77¡ãF can be approximated by the model r = 10,770 / d^2 - 0.37 for any wire diameter, d mils (1 mil = 0.001 inch), such that 5 ¡Ü d ¡Ü 100. What is the approximate resistance, in ohms, for such with a diameter of 50 mils?

F. 1
G. 4
H. 17
J. 215
K. 430

Answer 1

Such that 5 is less than or equal to d is less than or equal to 100. It wouldn't show the sign.

Answer 2

430