What is component 3 in figure T-1?

Component 3 in figure T-1 being identified as a lamp is supported by the characteristics that typically define such components in circuit diagrams. A lamp is often depicted as a circle with a filament inside or similar shapes that indicate illumination, differentiating it from other components like resistors or transistors.

When analyzing circuits, understanding the roles of these components is crucial. A lamp, when energized, produces light and has specific electrical properties related to its resistance and brightness characteristics. It serves a practical function in many circuit applications, which helps to confirm its identification.

On the other hand, resistors are denoted by zigzag lines, and transistors are represented by specific symbol structures indicating their ability to amplify signals or switch circuits on and off. A ground symbol usually appears as three lines stacked with the top line shorter than the others, indicating the reference point for the circuit's voltage levels. These distinct symbols help clarify the function and identity of various components in circuit design, further confirming that component 3 is a lamp.