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- January 27th 2007, 02:11 PM #1
## proof2

Hey MathForum,

Im not sure if this is for this section.

The field strength of a magnet*(H)*at a point on the axis, distance from its centre, is given by

where*2l*= length of magnet and*M*= moment. Show that, if*l*is very small compared with , then

How would you solve this question?

Thanks

- January 27th 2007, 02:31 PM #2

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- January 28th 2007, 03:07 AM #3

- January 28th 2007, 04:29 AM #4

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- January 28th 2007, 06:56 AM #5

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Hello, dadon!

The field strength of a magnet at a point on the axis,

distance from its centre, is given by: .

where = length of magnet and = moment.

Show that, if is very small compared with , then: .

Combine the fractions: .

The equation becomes: .

If is very small compared to , .then is even smaller.

If we consider to be negligible (virtually zero),

. . the formula becomes: .

- January 28th 2007, 09:14 AM #6

- January 28th 2007, 09:53 AM #7

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- January 30th 2007, 01:15 PM #8

- January 31st 2007, 12:58 PM #9

- February 3rd 2007, 10:08 AM #10

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- February 3rd 2007, 02:26 PM #11