The coil turns ratio in transformers directly affects what aspect of the transformer?

The coil turns ratio in transformers is crucial because it defines the relationship between the number of turns of wire on the primary winding (input side) and the number of turns on the secondary winding (output side). This ratio directly determines the voltage levels across the windings. According to the transformer principle, if the turns ratio is greater than one, it steps up the voltage from primary to secondary; if it is less than one, it steps down the voltage.

This means that changes in the turns ratio will alter the output voltage. The relationship is dictated by the formula: Voltage across primary / Voltage across secondary = Turns on primary / Turns on secondary. Therefore, the correct answer reflects the fundamental operation of a transformer as it manages voltage levels based on the turns ratio.

In contrast, while power generation efficiency can be influenced by various factors, like the materials used and design, it is not directly governed by the turns ratio. The physical size of the transformer and the type of core material used are affected by design specifications and operational requirements rather than by the coil turns ratio itself.