Logic circuits

When is the output of a 2-input OR gate 0?

  1. AWhen the two inputs differ
  2. BWhen both inputs are 0
  3. CWhen both inputs are 1
Show answer and explanation

Answer: B. When both inputs are 0

An OR gate (logical sum) outputs 1 if at least one input is 1. Its output is therefore 0 only when all inputs are 0.

  • A. When the inputs differ, the OR output is 1.
  • B. Correct. OR outputs 0 only when all inputs are 0.
  • C. When both inputs are 1, the OR output is 1.
Practice this topic Back to topic

More Logic circuits questions

  1. Which correctly describes what a NOT gate (inverter) does?
  2. Which is the decimal number 13 in binary?
  3. How many rows does the truth table of a 3-input logic circuit have?
  4. How many bits are in one byte?
  5. What is the hexadecimal number 1A in decimal?