(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Your friend wants to be a magician and intends to use Earth's magnetic field to suspend a current-carrying wire above the stage. He asks you to estimate the minimum current needed to suspend the wore just above Earth's surface at the equator (where the Earth's magnetic field is horizontal). Assume the wire has a linear mass density of 10g/m. Would you advise him to proceed with his plans for this act?

2. Relevant equations

dF=IdlxB, where dlxB is a cross product

3. The attempt at a solution

I am having trouble understanding where to start. I am having trouble visualizing the problem and I don't know how to incorporate the linear mass density into anything. My book does not go over anything like this. Help on how to start would be much appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Currents and magnetic fields

**Physics Forums | Science Articles, Homework Help, Discussion**