system
Given the following post, respond as if you're commenting on Reddit:
human
Is there a practical upper limit on the voltage increase I can get from a transformer before a significant loss in efficiency? What is the relationship between the efficiency and turns ratio of a transformer?
gpt
The only practical upper limit of voltage is dielectric breakdown.

The relationship between turns and efficiency should really just be driven by the resistance of the wire, the air or other core doesn't 'care' if a field is created by a higher current or more turns, it's behavior remains the same all the way through saturation.  (Neglecting edge effects)