Deck 8: Electrical Conductors and Wire Sizes

Question 1

The resistance of a circuit or conductor is usually constant and does not depend upon either current or voltage.

Answer 1

True

Question 2

State the formula to calculate the resistance of a conductor of a given length and diameter. Define each term in the formula (including units).

Answer 2

R=KL/CM
Where: R=resistance in ohms; K=resistance per mil-foot of the wire; L=length of conductor in feet; and CM=cross-sectional area in circular mils

Question 3

Find the CSA in circular mils of a wire 1/50 inch in diameter.

Answer 3

1/50 inch = 0.020 inch
0.020 inch = 20 mils
(20)2 = 400 circular mils

Question 4

If the current is excessive, the temperature may rise and cause a(n) ____________________ in resistance.

Question 5

____________________ is the best conductor of electricity.

Question 6

If a conductor produces heat faster than it is dissipated, the conductor may ____________________.

Question 7

A 250,000 circular mil conductor is designated 25 kcmil.

Question 8

The resistance of any conductor is directly proportional to its length.

Question 9

Any circuit with three 6 $\Omega$ resistors and one 2 $\Omega$ resistor will have a total resistance 20 $\Omega$

Question 10

The resistance of a conductor is ____________________ to its CSA.