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Cade
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[Solved] Find electric and magnetic field amplitudes in an electromagnetic wave
Find the electric and magnetic field amplitudes in an electromagnetic wave that has an average energy density of 1 J/m^3
u = Energy density
u = (1/2)(e0)(E^2) + (1/2)(B^2/u0)
or u = (e0)(E^2)
or u = (B^2)/u0
E = cB, c = speed of light
Let's find E first:
u = e0*E^2
E = sqrt(u/e0) = sqrt(1/(8.85*10^-12)) = 336146 V/m
336146 V/m is apparently wrong for E. Let's try B instead
u = (B^2)/u0
B = sqrt(u*u0) = 0.001121 T
Now let's try E = cB to find E
E = (3*10^8)(0.001121) = 336300 V/m
But both E and B are wrong. What am I missing? Percent error tolerance for a correct answer is 10%.
Homework Statement
Find the electric and magnetic field amplitudes in an electromagnetic wave that has an average energy density of 1 J/m^3
Homework Equations
u = Energy density
u = (1/2)(e0)(E^2) + (1/2)(B^2/u0)
or u = (e0)(E^2)
or u = (B^2)/u0
E = cB, c = speed of light
The Attempt at a Solution
Let's find E first:
u = e0*E^2
E = sqrt(u/e0) = sqrt(1/(8.85*10^-12)) = 336146 V/m
336146 V/m is apparently wrong for E. Let's try B instead
u = (B^2)/u0
B = sqrt(u*u0) = 0.001121 T
Now let's try E = cB to find E
E = (3*10^8)(0.001121) = 336300 V/m
But both E and B are wrong. What am I missing? Percent error tolerance for a correct answer is 10%.
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