Which symbol represents a NOT logic gate in standard digital circuit diagrams?

Which symbol represents a NOT logic gate in standard digital circuit diagrams?

• A. Rectangle labeled NOT
• B. Triangle with dot
• C. Circle
• D. Triangle with line

Answer: (B)

In digital diagrams, the NOT gate is shown as a triangle that indicates signal direction, with a small circle at the output to mark negation. The triangle communicates that the input is passed through a gate, and the inversion circle (the dot) flips the logic level, turning true into false and vice versa. So a triangle with a dot is the standard inverter symbol because it clearly combines the directional shape of a gate with the inversion indicator. A rectangle labeled NOT isn’t the conventional gate symbol you’d expect in schematic drawings, even though it conveys the function. A circle alone is just an inversion bubble, not a complete gate. A triangle with a line lacks the inversion marker and is typically used for other purposes, like buffering, not for indicating a NOT operation.

In digital diagrams, the NOT gate is shown as a triangle that indicates signal direction, with a small circle at the output to mark negation. The triangle communicates that the input is passed through a gate, and the inversion circle (the dot) flips the logic level, turning true into false and vice versa. So a triangle with a dot is the standard inverter symbol because it clearly combines the directional shape of a gate with the inversion indicator.

A rectangle labeled NOT isn’t the conventional gate symbol you’d expect in schematic drawings, even though it conveys the function. A circle alone is just an inversion bubble, not a complete gate. A triangle with a line lacks the inversion marker and is typically used for other purposes, like buffering, not for indicating a NOT operation.