What are the three terminals of an SCR?

The three terminals of a Silicon Controlled Rectifier (SCR) are indeed the anode, gate, and cathode. The anode is the positive terminal where the current flows into the device, while the cathode is the negative terminal where the current exits. The gate terminal allows for control of the SCR, enabling it to switch on or off when a small current is applied. This functionality is crucial in applications such as power regulation and switching.

In contrast, the other options reference terminals from different semiconductor devices, which highlights their distinctions. For example, the first option mentions the base and collector, which are associated with a bipolar junction transistor (BJT). The third option includes emitter and collector, also relevant to BJTs. The last option refers to a field-effect transistor (FET) with source, drain, and gate. These differences in terminal names are fundamental to understanding various semiconductor devices and their unique properties and functionalities.