🔍 Key Concepts

• Look closely at the small motor symbol where the rotor leads M1, M2, M3 enter the motor – the internal connection pattern of the three rotor phases is shown there. • Recall the difference between wye (Y) and delta (Δ) three‑phase connections: wye has three windings meeting at a common point, delta forms a closed triangle loop. • Notice how each rotor lead goes through its own bank of resistors and whether any of the three phase circuits are tied together outside the motor (which can help eliminate series‑parallel and open delta options).

💭 Think About

• On the internal rotor diagram, do the three windings join at a single junction point, or do they connect end‑to‑end in a loop of three segments? • How many rotor circuits are actually in use here: three separate phases, or only two (which would be necessary for an open delta) ? • Does the resistor bank arrangement change the basic three‑phase configuration of the rotor windings, or does it simply add resistance in series with each phase? What does that tell you about which answers can be ruled out?.

✅ Before You Answer

• Verify whether the rotor windings inside the circle form a common junction point (typical of one specific configuration) or a closed triangle (typical of another). • Confirm that all three rotor leads M1, M2, and M3 are used and that no two phases are intentionally left out, which would be required for an open delta. • Check that the resistors are only in series with each individual phase and do not create any parallel paths between phases, helping you rule out series‑parallel as the rotor configuration.