🔍 Key Concepts

• Difference between normally open (NO) and normally closed (NC) relay contacts in schematic symbols • How IEC-style contact symbols show an open gap versus a closed path • How extra slanted or angled lines on a contact symbol often indicate mechanical actuation or change of state

💭 Think About

• Look at symbols E, F, H, and J and ask: which one shows a path that is open (no current flow) in its normal, unenergized state? • Compare E and F: which looks like a simple contact that is not touching yet, versus one that already shows a closed connection or break line? • For H and J, think about whether the added angled lines and dots are showing a switch with an actuator rather than a basic relay contact symbol.

✅ Before You Answer

• Identify which symbol shows two separated contact lines with no diagonal line crossing them – this is the key sign of a normally open contact. • Verify that you are choosing a basic relay contact symbol, not a limit switch or mechanically operated switch (often shown with extra levers or dots). • Confirm that the symbol you pick would only conduct after the relay coil is energized, not in its normal resting state.