What is component 6 in figure T-2?

In schematic Figure T-2, component 6 is represented by two parallel lines, with one straight and one typically curved. This is the standard schematic symbol for a capacitor, specifically a polarized (electrolytic) capacitor commonly used for filtering in power supplies. Capacitors are designed to store electrical energy in an electric field. The parallel lines in the schematic symbol directly represent the two conductive plates found inside a physical capacitor. Distractors like a resistor would appear as a zig-zag line, while a transistor would be drawn as a circle with three connecting leads. Recognizing the simple parallel plates is key to identifying capacitors on any exam diagram.