Calculating Magnetic Fields and Induced EMFs: Help Needed!

AI Thread Summary
To calculate the magnetic field produced by a power line carrying 50Hz alternating current, the formula B = [N(mu_0)I]/2R is applicable, where N is the number of turns, mu_0 is the permeability of free space, I is the current, and R is the distance from the wire. For the given parameters, the magnetic field at the coil can be determined using this equation. To find the induced emf in the coil, the change in magnetic flux over time is essential, with the relationship dI/dt = 2*pi*f*I being relevant for alternating current. The discussion highlights the importance of understanding the relationship between magnetic flux and induced emf, especially in non-constant magnetic fields. Clarification on these concepts aids in solving the problem effectively.
WY
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Hey
I'm wondering if someone can help me out with this question.

Q: In order to measure the magnetic fields produced by the power lines carrying 50Hz alternating current, a coil consisting of 1500 turns of area 5cm^2 as constructed. Suppose that there is a single power line carrying a current which has an amplitude of 800A and that the coil is 10m from the wire.
a) What is the magnitude of the magnetic field at the coil
I found this using B =[N(mu_0)I]/2R
b) What is the magnitude of the induced emf in the coil?

I'm stumped on B :confused: could anyone point me in the right direction? I was using the idea that change in flux over time can be used to find induced emf and that in an alternating curret dI/dt=2*pi*f*I - but the problem is that i don't know where to go from there.

Thanks in advance!
 
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The magnetic field is not constant.
Write the equation for the current as a function of time.
 
thanks for the quick reply - but i don't quite understand how this ties in with finding the emf using the change in flux over the change in time.
 
oh i see now! sorry - I wasn't thinking properly! Thanks again :)
 

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