__________-ratio is the number of turns of wire in the primary winding compared to the number of turns in the secondary winding.

• A. Turns
• B. Voltage ratio
• C. Current ratio
• D. Impedance ratio

Answer: (A)

The number of turns on the primary compared to the secondary defines the transformer turns ratio. This ratio, written as Np/Ns, directly determines how voltages and currents are transformed in an ideal transformer: Vp/Vs ≈ Np/Ns and Ip/Is ≈ Ns/Np. If the primary has more turns, the secondary voltage drops (step-down); if the secondary has more turns, the voltage rises (step-up). The term that fits the blank is turns, since it’s the count of windings being compared. The other options describe resulting quantities (voltage, current, impedance) rather than the actual count of turns used to form the ratio, though they are related through the transformer equations.