# Value of line integral

1. Dec 14, 2008

### lovinuz

1. The problem statement, all variables and given/known data
There is a constant electric field E = E0sin(kz+wt+pi/3) k(direction vector). What is the value of the line integral(P) B.dl, where P is a circular path, centered on the origin, lying in the xy-plane, having radius r?

2. Relevant equations
integral E.dl = -dI/dt

3. The attempt at a solution
I am having difficulty approaching this question, can someone please give me some kind of push? Thanks.

2. Dec 14, 2008

### James R

First, that isn't a constant electric field. It varies with time.

$$\int B.dl = +\epsilon_0 \mu_0 \frac{d\Phi_E}{dt}$$