🔍 Key Concepts

• Review the typical symbol of a diac trigger diode and how it differs from a normal diode or triac. • Compare devices that are bidirectional (can conduct in both directions) versus unidirectional. • Notice which symbols in EL-0065 have a gate terminal and which do not.

💭 Think About

• Which numbered symbol on the sheet shows a device that can conduct in both directions but has only two terminals (no gate)? • Look closely at 9 and 10: how does removing the gate from one of these change the type of device it represents? • Which of the choices 7–10 clearly shows only anode–cathode with a single arrow (one-direction conduction)? Eliminate that from consideration for a diac.

✅ Before You Answer

• Verify that a diac symbol looks like two opposing diodes or thyristors inside one circle and has only two external leads. • Confirm that any symbol with a labeled gate (G) is not a plain diac trigger diode. • Make sure the symbol you pick is not a standard one-way rectifier diode or zener diode symbol.