Is there a formula showing the relationship between the number of iron cores and the output voltage of a transformer?

I know the relationship between number of turns, current and voltage of a transformer, but is there a formula showing the relationship between the number of iron cores and the output voltage of a transformer?

$$\frac{N_p}{N_s}=\frac{V_p}{V_s}=\frac{I_s}{I_p}$$

Just like the equations above, is there a approximate relationship between $$n$$ number of iron cores and the voltage output of an electromagnet?

• What do you mean by the number of iron cores? Typically transformers have a single core. – M. Enns Jul 21 at 18:38