# Magnitude of Flux Density

1. Feb 7, 2010

### Kev1n

1. A loop of wire between the poles of a magnet, the magnetic field is uniform between the poles. The are of the loop of wire within the field is 20cm sqaured. Determine the magnitude of flux density required to induce a mx voltage of 1v when the loop is rotated at 600rpm

2. B= Flux x A

3. I know A however cant figure out where to go next, any pointers please. I am not asking to be solved just pointers please

2. Feb 7, 2010

### xcvxcvvc

$$\frac{d\phi_m}{dt} = V_{induced}$$
And
$$\phi_m = \int\limits_{A}^{}B}\, dA=BAcos(\theta)$$

$$V_{induced}=\frac{d(BAcos(\theta))}{dt}$$

You need to relate $$\theta$$ to time and use that last equation I gave you to solve for $$B$$