- #1

roam

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## Homework Statement

A flat coil of wire consisting of 20 turns, each with an area of 50 cm

^{2}, is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 2.0 T to 6.0 T in 2.0 s. If the coil has a total resistance of 0.40 Ω , what is the magnitude of the induced current?

## Homework Equations

[tex]B= \mu_0 \frac{N}{l} I[/tex]

[tex]\Phi_B = \int B.dA[/tex]

[tex]L=\mu_0 N^2 A[/tex]

[tex]L=\frac{\Phi_B}{I}[/tex]

## The Attempt at a Solution

Using the above equations and rearranging we get

[tex]I=\frac{\Phi_B}{\mu_0N^2A}[/tex]

[tex]I=\frac{\Phi_B}{(4\pi \times 10^{-7}) 20^2 (0.5)}[/tex]

Now how do I evaluate the flux? I use [tex]\Phi_B = LI[/tex], then the I's will cancel and I can't solve the problem...

Are there simpler ways of solving this problem? How do I need to make use of dB/dt which is given to us?