In a transformer, what happens when an open circuit occurs in the secondary winding?

When an open circuit occurs in the secondary winding of a transformer, the primary winding experiences a change in its operating conditions. In this situation, the secondary winding, which is typically where the output voltage is delivered, is not completing a circuit, meaning that no current can flow through it.

As a result, this lack of current flow in the secondary does not draw any power from the primary winding. Consequently, the primary winding will not experience an increase in current flow, as there is no load to supply power to. This keeps the primary current negligible, allowing the transformer to continue operating under no-load conditions.

The transformer indeed operates in a state where the primary still receives its supply voltage, but with no associated load in the secondary, there is little to no current draw. It's important to understand that while the primary voltage is present, the transformer's magnetizing inductance keeps the core magnetized, maintaining its ability to transfer voltage despite the absence of load. Therefore, the correct conclusion about the situation where an open circuit occurs in the secondary winding is that no current flows in the primary winding.