On a DC schematic, which symbol represents the positive terminal of the source?

• A. the curved line
• B. the color red
• C. the larger bar
• D. the smaller bar

Answer: (C)

In a DC source symbol that uses two lines, the longer line indicates the positive terminal and the shorter line indicates the negative terminal. So the positive terminal is shown by the larger bar because it visually represents a higher potential. The curved line isn’t the standard way to mark a positive terminal, and color alone (like red) isn’t a symbol in the schematic itself. The smaller bar represents the negative terminal, not the positive.