The average emf created by the earths magnetic field.

In summary, the average emf created by the earth's magnetic field is approximately 25 microvolts per meter and is generated by the movement of molten iron in its core. Its purpose includes protecting the planet from harmful solar winds and radiation, aiding in navigation, and contributing to the formation of auroras. While there is no evidence of significant effects on living organisms, some animals use it for navigation. The average emf can also change over time, with the earth's magnetic field periodically reversing its polarity on a geologic timescale.
  • #1
mtmickush
2
0

Homework Statement


What is the average emf created by a 15 turn cable that is .5 meters in diameter, lies flat with the surface of the Earth and is flipped 180 degrees in 2 seconds?
*Assume the Earth produces a magnetic field of .5 micro Tesla.


Homework Equations



e=-n*r^2*delta B/delta T

The Attempt at a Solution



n=15
delta B=.5*10^-6 minus -.5*10^-6 =1*10^-6 Tesla.
Delta T= 2 seconds
r=.25

e=-.468 micro Volts?
 
Physics news on Phys.org
  • #2
e=-π*r^2*delta B/delta T
= π*(.25)²*(1x10^-6)/2 = .098 x 10^-6
 

1. What is the average emf created by the earth's magnetic field?

The average emf (electromotive force) created by the earth's magnetic field is approximately 25 microvolts per meter. This value can vary depending on location and time.

2. How does the earth's magnetic field create an emf?

The earth's magnetic field is created by the movement of molten iron in its core. This movement generates electric currents, which in turn creates the magnetic field. The interaction between the magnetic field and the earth's atmosphere and ionosphere results in the production of an emf.

3. What is the purpose of the earth's magnetic field?

The earth's magnetic field serves several important purposes. It helps protect the planet from harmful solar winds and radiation by deflecting them away from the surface. It also plays a crucial role in navigation for animals and humans, as well as aiding in the formation of auroras.

4. Does the average emf created by the earth's magnetic field have any effects on living organisms?

While there is ongoing research in this area, currently there is no evidence to suggest that the average emf created by the earth's magnetic field has any significant effects on living organisms. However, some animals, such as birds and turtles, use the earth's magnetic field for navigation.

5. Can the average emf created by the earth's magnetic field change over time?

Yes, the average emf created by the earth's magnetic field can change over time. In fact, the earth's magnetic field has been known to reverse its polarity periodically, which can result in changes in the average emf. These reversals happen on a geologic timescale, with the last one occurring approximately 780,000 years ago.

Similar threads

  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
981
  • Introductory Physics Homework Help
Replies
6
Views
712
  • Introductory Physics Homework Help
Replies
7
Views
783
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
877
  • Introductory Physics Homework Help
Replies
4
Views
394
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
25
Views
208
  • Introductory Physics Homework Help
Replies
8
Views
2K
Back
Top