What does a transformer's turns ratio determine in practical circuits (assume linear operation)?

Introduction / Context:
The turns ratio N_p:N_s is the key parameter of a transformer. It dictates how voltage, current, and impedance appear from one side to the other. Recognizing these relationships allows designers to step voltages up or down, match impedances, and manage current levels safely and efficiently.

Given Data / Assumptions:

• Linear transformer behavior around the intended operating point.
• Idealized relationships are used to explain the principle (real transformers include losses).
• Sinusoidal steady-state operation.

Concept / Approach:
Fundamental equations: V_s / V_p = N_s / N_p. Currents are inversely proportional: I_s / I_p = N_p / N_s. Impedance reflects by the square of the turns ratio: Z_reflected = (N_p / N_s)^2 * Z_load (as seen from the primary). Therefore, turns ratio simultaneously sets voltage ratio, current ratio, and impedance transformation.

Step-by-Step Solution:

Verification / Alternative check:
Example: N_p:N_s = 2:1 → V halves, I doubles, and a 16 Ω load looks like 64 Ω from the primary. Measurements on a bench transformer corroborate these proportionalities.

Why Other Options Are Wrong:

• Each individual statement (voltage, current, impedance) is true, but considering the whole picture, the correct comprehensive choice is ”all of the above.”

Common Pitfalls:
Forgetting the square-law for impedance reflection or mixing up the direction of the ratio (Ns/Np vs. Np/Ns).

Final Answer:
all of the above