š Key Concepts
ā¢ Difference between bipolar junction transistors (BJT) and field effect transistors (FET) symbols
ā¢ How a JFET (junction field-effect transistor) symbol shows the gate, source, and drain without an insulated gate oxide
ā¢ How extra leads like a substrate/body (Sub) terminal usually indicate a MOSFET rather than a JFET
š Think About
ā¢ First, identify which numbered symbols clearly show a BJT (base, collector, emitter) and eliminate those choices.
ā¢ Then, among the remaining FET-looking symbols, decide which one represents a JFET by looking for a gate that is directly connected to the channel (a PN junction), not separated by insulation.
ā¢ Check whether the symbol includes a separate substrate/body terminal; ask yourself which FET type typically exposes that as a separate lead.
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Before You Answer
ā¢ Verify which symbols are labeled with B, C, E (base, collector, emitter) ā those are BJTs, not JFETs.
ā¢ Among the FET symbols, look for the one that has only three terminals labeled G, D, and S, with no extra Sub (substrate) lead.
ā¢ Confirm that the gate in the correct symbol appears to form a junction directly into the channel, rather than being drawn as an insulated plate as in a MOSFET.