Flux Linking in secondary coil for Toroidal Transformer problem...

HPRF

1. The problem statement, all variables and given/known data

A toroidal transformer has been built. It has a square section 'doughnought' shaped non-magnetic core, inner radius 'a' and height 'h' around which the secondary transformer has been wound 'n' times. Calculate the flux linking the secondary due to a time dependent current flowing in the primary which is straight and long compared to the toroid dimensions, but passes through the toroid core at a radial position a/2.


2. Relevant equations

Thinking of using the integral form of Faraday's Law or the Boit Savart equation. Leaning towards Faraday's Law as it seems to be a current independent problem.


3. The attempt at a solution

I'm unsure of were to even start. (Any advice would be great!)