Question T6B05
From subelement T6 - T6B
What type of transistor has a gate, drain, and source?
Why is this correct?
Field-effect transistors (FETs) have three electrodes named gate, drain, and source. The gate controls current flow using voltage (creating an electric field, hence 'field-effect'). Bipolar junction transistors have emitter, base, and collector instead. Varistors are voltage-dependent resistors, not transistors. Tesla-effect transistors don't exist as a standard component type.
Memory tip
Remember the naming pattern: FET electrodes describe function (gate controls, drain/source are endpoints), while bipolar transistors use position names (emitter sends, collector receives, base controls). The 'field-effect' name directly hints at voltage control creating electric fields.
Learn more
FETs use voltage control rather than current control, making them ideal for low-power switching applications in amateur radio equipment. The gate acts like a valve controlled by electric field strength, allowing precise control of current flow between drain and source. This voltage-controlled operation gives FETs advantages in RF amplifiers and digital circuits where input impedance and power consumption matter for efficient station operation.
Think about it
Why do you think FETs use voltage control while bipolar junction transistors use current control, and how might this difference affect their use in amateur radio circuits?