Two-phase generation – Orthogonal coil placement Statement: “A simple two-phase generator consists of two conductive loops separated by 90°, rotating in a magnetic field.” Evaluate this statement.

Introduction / Context:Before three-phase became dominant, two-phase systems (quadrature-phase) were used in early power and control applications. Understanding their geometry helps with quadrature signal generation used today in communications and motor control (e.g., rotating fields from orthogonal windings).

Given Data / Assumptions:

• Two identical coils placed with electrical angle separation.
• Uniform rotating magnetic field provided by a rotor (field winding or permanent magnet).
• Goal: produce two sinusoidal voltages in time quadrature (90° apart).

Concept / Approach:

Two coils displaced by 90° electrical experience flux linkages that peak at times differing by a quarter cycle. The induced EMFs are equal in magnitude (ideally) and shifted by ±90°, forming a two-phase system suitable for certain motors and signal-processing tasks.

Step-by-Step Solution:

Verification / Alternative check:

Phasor representation shows perfect quadrature. In vector control of AC machines, similar orthogonal components (d–q axes) are synthesized electronically.

Why Other Options Are Wrong:

Requiring 120° is a three-phase property, not two-phase. Rotor type is irrelevant to the quadrature requirement; the electrical separation defines the phase relationship.

Common Pitfalls:

Mixing mechanical with electrical degrees in multi-pole machines; overlooking amplitude balance due to winding factors.

Final Answer:

True.