A bare 4 AWG copper conductor Installed horizontally near the bottom or vertically, and within that portion of a concrete foun dation or footing that is In direct contact with the earth, can be used as a grounding electrode when the conductor is at least ft in length.

20 ft

Explanation:

This is the length where the direct contact could be used as ground electrode

divide the right side by the left side

0.024÷1.2=0.02 for example

step-by-step explanation:

we are given

we have to simplify it

firstly, we will factor it

now, we can cancel like terms

now, we can combine it

so, we get