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## What is nominal ratio of transformer?

In instrument transformers, the nominal ratio is the ratio of rated primary winding quantity to the rated secondary winding quantity. In current transformers, nominal ratio **= rated primary current/rated secondary current**. In potential transformers, nominal ratio = rated primary voltage/rated secondary voltage.

## What is the relation between turns ratio and current in a transformer?

The current in the windings of a transformer is **inversely proportional to the voltage in the windings**. This relationship is expressed in below Equation. Since the voltage ratio is equal to the turns ratio, we can express the current ratio in terms of the turns ratio, as in below Equation.

## What is difference between turns ratio and transformation ratio?

The transformation ratio is defined as the ratio of the secondary voltage to primary voltage. And Turns Ratio would be **the number turns of the primary winding to the secondary winding** (edit: those were swapped originally). Some transformers have multiple secondary windings as well to create multiple outputs.