Question

a conductor thats described as a 750 mcm wire has an area of
a) 750,000 kcmils.
b) 750 in².
c) 750 cmils.
d) 750 kcmils
question 3 (5 points)
listen
luis is installing some 12 - gage wire. how much resistance will there be throughout a
distance of 400 feet?
a) 1.011 ohms
b) 0.792 ohms
c) 0.519 ohms
d) 0.529 ohms

Explanation:

Step1: Recall the formula for resistance

The formula for resistance \(R=
ho\frac{l}{A}\), where \(
ho\) is the resistivity (for copper, \(
ho = 10.4\ \Omega - cmil/ft\)), \(l\) is the length of the wire, and \(A\) is the cross - sectional area. For 12 - gauge wire, the cross - sectional area \(A = 6530\ cmil\).

Step2: Substitute the values into the formula

Given \(l = 400\ ft\) and \(A=6530\ cmil\), \(
ho = 10.4\ \Omega - cmil/ft\). Then \(R=
ho\frac{l}{A}=10.4\times\frac{400}{6530}\)

Step3: Calculate the value

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Wait, there is a mistake. Maybe using the standard formula \(R = \frac{K\times L}{CM}\), where for copper \(K = 12.9\) (at \(75^{\circ}F\)) for DC resistance. \(L = 400\ ft\), \(CM\) (circular mils) for 12 - gauge wire \(CM=6530\)

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Answer:

B. \(0.792\) ohms