🔍 Key Concepts

• TRIAC stands for a bidirectional AC switching device used in power control circuits • Compare TRIAC terminals to those of a BJT transistor and a thyristor (SCR) • Remember that a TRIAC is essentially like two SCRs connected in opposite directions

💭 Think About

• Which option uses terminal names that you normally see with bipolar junction transistors (BJTs)? Eliminate that. • Which option uses terminal names that you normally see with FETs/MOSFETs? Eliminate that. • For a device that can conduct in both directions on an AC line, what would you expect the two main power terminals to be called, and what is the control terminal called?

✅ Before You Answer

• Identify which choices mention emitter, base, collector — those usually belong to BJTs, not TRIACs. • Identify which choice mentions gate, source, and drain/sink — those are typical FET/MOSFET terminals, not TRIACs. • Confirm that the remaining option has one control terminal and two main current-carrying terminals appropriate for a bidirectional AC device.