Question T6B04
From subelement T6 - T6B
Which of the following components can consist of three regions of semiconductor material?
Why is this correct?
Transistors are constructed from three regions of semiconductor material arranged in layers. Bipolar junction transistors have either PNP or NPN configurations - two P-type regions with an N-type sandwiched between (PNP) or two N-type regions with a P-type between (NPN). Each region connects to an electrode (emitter, base, collector). The other options are wrong: alternators are rotating electrical machines, triodes are vacuum tubes with three electrodes but no semiconductor regions, and pentagrid converters are specialized vacuum tubes.
Memory tip
Remember the pattern: semiconductor components with three terminals typically have three regions of semiconductor material. The 'three' connection helps distinguish transistors from diodes (two regions) and more complex semiconductors. This structural knowledge applies across all transistor types.
Learn more
In practical amateur radio circuits, transistors serve as the fundamental building blocks for amplifiers, oscillators, and switching circuits. Understanding their three-region semiconductor structure helps explain why they can control current flow and provide gain. The emitter-base junction acts like a diode controlling current flow to the collector, enabling both amplification and switching functions essential in transmitters, receivers, and power supplies.
Think about it
Why do you think having three regions of semiconductor material allows a transistor to both amplify signals and act as an electronic switch?