The change in voltage is directly proportional to the ratio of the number of turns in the primary coil to the number of turns in he secondary coil. Transformer law of voltage. V₂ / V₁ = N₂ / N₁ Formula for the transformer law of voltage.

What is the principle of the transformer which law?

The transformer works on the principle of Faraday's law of electromagnetic induction and mutual induction.

What is the theory of transformer?

A transformer works on the principle that energy can be transferred by magnetic induction from one set of coils to another set by means of a varying magnetic flux. The magnetic flux is produced by an AC source.