# Induced EMF Question

**1. The problem statement, all variables and given/known data**

A rectangular wire loop, 24mm by 36mm, is placed in a magnetic field. The flux density perpendicular to the loop is decreasing in magnitude at a rate of 0.2Wb/[itex]m^{2}[/itex]/s. Calculate the induced emf around the loop.

**2. Relevant equations**

The problem is I don’t know which equation applies to this question. I know that 0.2Wb/[itex]m^{2}[/itex]/s = [itex]\frac{d\phi}{dt}[/itex] but as far as I was concerned from what I have read so far is that you would need to know the number of loops to get the answer to this question.

**3. The attempt at a solution**

I know that the answer is 0.17mV. I managed to get this answer by multiplying the dimensions together 24mm x 36mm = 8.64x[itex]10^{-4}[/itex] then multiply this by 0.2. But I don’t understand why this this is the method, if someone could explain this for me I would greatly appreciate it :biggrin:

http://ift.tt/1jDOgQr

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