Calculating Magnetic Fields and Induced EMFs: Help Needed!

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Homework Help Overview

The discussion revolves around calculating magnetic fields and induced electromotive forces (EMFs) related to a coil near a power line carrying alternating current. The original poster presents a specific problem involving a coil with given parameters and seeks assistance with the calculations.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to calculate the magnetic field using a formula and expresses confusion regarding the induced EMF, particularly in relation to the change in magnetic flux over time. Some participants question how the time-varying nature of the current affects the calculations.

Discussion Status

The discussion is ongoing, with participants exploring the relationship between the magnetic field and induced EMF. Some guidance has been offered regarding the need to express the current as a function of time, but there is no explicit consensus on the next steps or resolution of the problem.

Contextual Notes

The original poster is working within the constraints of a homework assignment, which may impose specific methods or approaches to be used in the calculations. There is an indication of uncertainty regarding the application of concepts related to changing magnetic fields and induced EMF.

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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