Which symbol is used to represent a resistor in schematics?

• A. Box with diagonal line inside
• B. Circle with R
• C. Rectangle
• D. Long squiggly line

Answer: (D)

The symbol for a resistor in schematics is the long squiggly line. This traditional zigzag design was chosen to clearly indicate a passive resistive element and to stand out from other components on a schematic, making it easy to recognize at a glance. While some modern standards use a simple rectangle to represent a resistor, the squiggly line is the form most commonly taught and used in many practice exams and textbooks.

Other shapes shown don’t represent a resistor in the common schematic conventions: a box with a diagonal inside isn’t the resistor symbol, a circle with an R isn’t a standard resistor symbol, and a rectangle, while used in some IEC-style drawings, is not the symbol highlighted in this context.