🔍 Key Concepts

• Standard symbols for basic logic gates (AND, OR, NOT) • Meaning of the small circle (bubble) on a gate output • Difference between single-input and two-input logic gates

💭 Think About

• Look at how many inputs go into figure 7 and compare that to the inputs shown on the other gates in the illustration. • Ask yourself what the triangle shape with a small bubble on the output usually represents in digital logic diagrams. • Consider which of the answer choices normally require two inputs to produce an output based on a truth table.

✅ Before You Answer

• Verify which gate symbol consists of a triangle with one input and a bubble on the output. • Confirm that NAND, XOR, and XNOR are usually drawn with two or more inputs, not just one, in standard logic symbols. • Make sure the function of the symbol you recognize matches the idea of signal inversion (output is the opposite of input).