The average emf created by the earths magnetic field.

[mtmickush]

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?

 

[Delphi51]

e=-π*r^2*delta B/delta T
= π*(.25)²*(1x10^-6)/2 = .098 x 10^-6