voltage drop. please help.

[aherman]

I'm doing a study guide for my journeyman card and I'm having a little drop. I'm not that familiar with OHM's law so maybe you guys could help me out.

Here is my question.
Given the branch circuit below, determine the voltage drop.
Resistance of 3 ohms/1000ft
Length of circuit 500 ft.
current= 6 amps.

What is the voltage drop and can you please help explain the formula used to find it. Thanks!

 

[charlie b]

Ohm's Law tells us that voltage is equal to current times resistance. The formula is E = IR.

You have 500 feet of wire that has a resistance of 3 ohms per 1000 feet. That will tell you the total resistance.
Multiply that value by the current value that they gave you, and you will have the voltage across (i.e., being dropped by) the wire.

 

[aherman]

so for the resistance what would the formula itself be? (500x3) divided by 1000?

 

[aherman]

nevermind i got it. Thanks a bunch.

 

[jumper]

Start here: basic circuit analysis.

http://www.allaboutcircuits.com/vol_1/chpt_2/1.html

 

[jns]

so for the resistance what would the formula itself be? (500x3) divided by 1000?

Hmm, you have a conductor going from the source to the load and you another one coming back. Have you accounted for both?