Questions on electromagnet?

Question

For the equation: Restivity = pL/A

1. does R siginify the entire length of the copper wire, or from the head of the magnet to the end, what if I use the same wire to connect to a second solenoid?

2. What gauge wire would be best for 1.2 voltage

3. What is the magnetic permeability of different types of steel or iron?

Answer 1

1) Correct equation is Resistance = pL/A where p = resistivity

R indicates the resistance between wherever you measure the L. If L is end to end, then R is resistance end to end.

"what if I use the same wire to connect to a second solenoid?" what does this mean? If you put another solenoid in series, then the resistances add. If you put them in parallel, use the parallel resistance formula.

2) Depends on how much current the battery can supply and on how long the wire is.

3) see references

.