Question 361Electricity & Electronics - QMED

The correct answer is B) NPN bipolar junction transistor. The NPN bipolar junction transistor is the component labeled Q1 in the regulated DC power supply illustrated in section "D" of the diagram EL-0085. Bipolar junction transistors are commonly used in power supply circuits to regulate and control the flow of current, which is the primary function of the component labeled Q1 in this diagram. The other options are incorrect because a triac (A) is a type of semiconductor switch used for AC power control, a PNP bipolar junction transistor (C) is the opposite type of transistor with a different configuration, and a silicon controlled rectifier (D) is a specific type of semiconductor device used for power regulation, but not the one depicted in this circuit.