# Turn Ratio

## Definition - What does Turn Ratio mean?

Turn Ratio is the ratio of turns of a wire in a primary winding to the number of turns of a wire in the secondary winding of a transformer. In the form of an equation it can be expressed as:

Turn Ratio = Np/Ns

Where Np represents number of turns in the primary coil of a transformer and Ns represents number of turns in the secondary coil of a transformer.

## Petropedia explains Turn Ratio

A transformer is an electrical device that converts inbound electricity to a higher or lower value of voltage for specific purposes. It is a major component in power grid which helps in supplying voltage in many nations. A transformer has two main functions, i.e., to supply current from source to destination and regulate the voltage of the current.

It consists of a coil system that manages the current flow within a specific range. It has a primary winding (coil) and a secondary winding. The primary winding is energized by an AC source whereas the secondary coil delivers this AC to the load. Maximum power is transferred from one circuit to another through a transformer when the impedance is equal, or matched. A transformer winding constructed with a definite turn ratio can perform an impedance matching function. The turn ratio will establish the proper relationship between the primary and secondary winding impedance.