# Calculate EMF Induced

1. Jan 14, 2010

### Andromache

Can anyone point me in the right direction? I'm awful with electromagnetism.

Last edited: Jan 14, 2010
2. Jan 14, 2010

### Matterwave

Do you know Faraday's law? This is a pretty straight forward application of Faraday's law. Just do the EMF induced in 1 turn of the wire, and then multiply by 100 since there's 100 turns. It's just that simple.

3. Jan 14, 2010

### Andromache

It's finding the EMF induced in one turn that's the problem. I know EMF=-d$$\Phi$$/dt but I don't know how to find that when I'm just given the rate of increase of B.

4. Jan 14, 2010

### Matterwave

$$\Phi=\int_S{BdA}$$

Now, since the B field is constant over that surface, and is perpendicular to that surface:

$$\Phi=B*A$$

Therefore

$$\frac{d\Phi}{dt}=\frac{d(B*A)}{dt}$$

Can you figure it out from there?

5. Jan 14, 2010

### Andromache

Thanks for your help. Iurns out I was using the circumference rather than the area, which was giving me the wrong answer!