Earth magnetic field at equator is approximately 0.4,G then earth's dipole moment would be (near

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5.Magnetism and Matter

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Earth magnetic field at equator is approximately $0.4\,G$ then earth's dipole moment would be (nearly) (ralius of earth $= 6.4 \times 10^6\,m$ )

A

$1\times 10^{23}$

B

$2\times 10^{23}$

C

$.1\times 10^{23}$

D

$.2\times 10^{23}$

Solution

$B_{\varepsilon}=\frac{\mu_{0} M}{4 \pi r^{3}}$

$4 \times 10^{-5}=\frac{4 \pi \times 10^{-7} \times M}{4 \pi \times\left(6.4 \times 10^{3}\right)^{3}}$

$M=1.05 \times 10^{23}\, \mathrm{A}-\mathrm{m}^{2}$

Accordy to fleming left hand rule.

Standard 12

Physics

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