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The magnetic field 0.02 m from a wire is 0.1 T. What is the magnitude of the magnetic field 0.01 m from the same wire?

The magnetic field 0.01m from the wire is 0.2T.

Explanation:

The magnetic field at a distance due to a wire carrying current is

Now, let us call the magnetic field at and the magnetic field at :

Dividing by we get

Now we put in the numbers

and to get:

solving for we get:

which is the magnetic field at 0.01 meters from the wire.

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table