1. May 9, 2010

1. The problem statement, all variables and given/known data
A square of side 2cm, in the first quadrant of the x-y plane, with a corner at the origin, is in a magnetic field pointing out of the page of magnitude 4t2y.

Calculate the emf around the square at t = 2.5s and give its direction.

2. Relevant equations

$$\epsilon = - \frac{d}{dt} \Phi$$

3. The attempt at a solution

Do I do it like this?

$$\epsilon = -\frac{d}{dt} \int ^2 _0 \int ^2 _0 4t^2 y \ dx \ dy$$

If so, then great. If not, what do I do?

2. May 9, 2010

### alexgmcm

Yeah, that seems correct as you are just using the definition of flux:
$$\phi = \int \vec{B} \cdot \vec{dA}$$

And subbing that into your above expression for the emf.

It looks correct but I'm not certain as I'm only a mere first year so you should probably get someone else to confirm.

3. May 9, 2010

### stevenb

It looks correct, but I would double check the units of distance, magnetic field and voltage. What system of units are you using for Maxwell's equations? I normally use SI units with meters, Telsa and Volts, so I would have set my upper limits at 0.02 rather than 2. However, if you are using CGS units it may be correct - just double check it.

4. May 9, 2010