Activities/Turtle Art/Using Turtle Art Sensors: Difference between revisions

Revision as of 02:35, 4 February 2011 view source Tonyforster (talk \| contribs) 2,486 edits →Measuring DC amps ← Older edit		Revision as of 02:43, 4 February 2011 view source Tonyforster (talk \| contribs) 2,486 edits →Ampere's Law Newer edit →
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	*I in amps		*I in amps

	In the special case of a wire in free space, the integral is easy to evaluate. At a radius r, the field is uniform over a circular path round the wire , the path length is 2πr. So for the magnetic field B at a radius r from a wire in free space, ~~B2πr=u0I~~.		In the special case of a wire in free space, the integral is easy to evaluate. At a radius r, the field is uniform over a circular path round the wire , the path length is 2πr. So for the magnetic field B at a radius r from a wire in free space, [[File:B2Pir-equals-uoI.jpg]]