# Homework Help: How to find the turns ratio between the primary and secondary coils.

1. Mar 27, 2013

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

Find the turns ratio across the transformer such that a spark is given off at the points AB. The distance from point A to point B is 5.00 mm.

AB is the distance across the secondary coil.

The frequency and voltage of the primary coil is given.

2. Relevant equations

N_p /N_s = V_p / V_s = I_s /I_p

3. The attempt at a solution

I don't know where to start. I got it wrong. I was given the answer, but not the solution to the problem. Could I get some help on where to start?

2. Mar 27, 2013

### Staff: Mentor

What potential must exist between points A and B in order for a spark to jump the gap?

3. Mar 28, 2013

gneill,

Thanks for helping. I honestly don't know what I was thinking. I knew the potential of the secondary coil had to be the dielectric constant of air multiplied by the distance AB.

4. Mar 28, 2013

### Staff: Mentor

I think you mean the dielectric breakdown strength of air