🔍 Key Concepts

• How an autotransformer shares part of its winding between primary and secondary • What a tapped winding looks like in a diagram (extra terminals along a single coil) • How a Scott-connected or open-delta transformer normally uses two separate transformer cores/windings rather than a single shared one

💭 Think About

• Look at figure C and count how many separate windings are actually drawn. Are the primary and secondary clearly separate, or is one continuous winding with multiple taps? • Compare the number and placement of terminals (H1–H4 and X1–X4). Do some terminals clearly belong to the same physical winding, suggesting a common section? • Ask yourself which of the choices describes a transformer where one winding section serves both the high‑voltage and low‑voltage connections.

✅ Before You Answer

• Verify whether the diagram shows one common winding that both input and output leads connect to • Check if there are taps along a single coil (typical of a tapped step‑down) versus two distinct single‑phase units (Scott or open‑delta) • Confirm whether the configuration matches a transformer that can change voltage by using different tap points on the same winding.