Earth's Magnetic Dipole Moment

In summary, the Earth's magnetic dipole moment is 8.0 x 10^22 A m^2. The magnetic field strength on the surface of the Earth at the Earth's north magnetic pole is 6.17e-5 T, which is 1.23 times the typical field strength on the surface of the Earth (5.0 x 10^-5 T). To create a magnetic field on an earth-size planet without one, astronauts propose running a current through a wire around the equator. The necessary current would be equal to the magnetic dipole moment of the Earth, which is 8.0 x 10^22 A m^2.
  • #1
majormaaz
62
1

Homework Statement


The Earth's magnetic dipole moment is 8.0 x 1022 A m2.

(a) What is the magnetic field strength on the surface of the Earth at the Earth's north magnetic pole? You can assume that the current loop is deep inside the earth. 6.17e-5 T

(b)How does this compare to 5.0 x 10-5 T, the typical field strength on the surface of the earth?
1.23 times the typical field strength

(c)Astronauts discover an earth-size planet without a magnetic field. To create a magnetic field, so that compasses will work, they propose running a current through a wire around the equator. What size current would be needed? (Give the current necessary to produce a magnetic dipole equal to the earth's.)

Homework Equations


Bloop = (μ0/4∏)*(2AI/z3) --> on-axis magnetic field of a current loop/.
AI = magnetic dipole moment μ

The Attempt at a Solution


I'm confused as what to do, as it says to find a current necessary to produce a magnetic dipole, whereas the only term I'm familiar with in the context of this problem is the magnetic dipole moment AI. If someone could help me clarify which term I should be focusing on so that I can use the appropriate equation, that'd be great.
 
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  • #2
I think you might be overcomplicating part c). I would look at how the magnetic dipole is defined/derived and substitute the values in directly.
 
  • #3
paisiello2 said:
I think you might be overcomplicating part c). I would look at how the magnetic dipole is defined/derived and substitute the values in directly.

Yeah, I got the right answer. Basically, I was confused whether the magnetic dipole moment was the same thing as the magnetic dipole or not, but it turns out it is. Thanks!
 

What is Earth's Magnetic Dipole Moment?

Earth's magnetic dipole moment is a measure of the strength and orientation of the magnetic field produced by the Earth. It is a vector quantity, meaning it has both magnitude and direction.

How is Earth's Magnetic Dipole Moment measured?

Earth's magnetic dipole moment is measured using a device called a magnetometer. This instrument measures the strength and direction of the magnetic field at a specific location on Earth's surface.

What is the significance of Earth's Magnetic Dipole Moment?

Earth's magnetic dipole moment is significant because it plays a crucial role in protecting our planet from harmful cosmic radiation. It also helps with navigation and communication systems.

How does Earth's Magnetic Dipole Moment change over time?

Earth's magnetic dipole moment is not constant and has been known to change over time. This is due to the fluid motion of the Earth's molten iron core, which generates the magnetic field. The changes can be both gradual and abrupt.

What are the potential consequences of a weakening or reversal of Earth's Magnetic Dipole Moment?

A weakening or reversal of Earth's magnetic dipole moment could have significant consequences. It could lead to increased exposure to harmful radiation, disruptions in navigation and communication systems, and changes in animal migration patterns.

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