Logic diagrams questions and answers
Q1. Draw and label the logic gates for AND, OR and NOT.
A1. AND
OR
NOT
Q2. An AND gate has two inputs. Draw the truth table for this AND gate.
A2.
Q3. Why does a NOT gate only have one input?
A3. A NOT gate reverses the input. If there were more than one input, it would not be able to determine the output.
Q4. What is a logic gate?
A4. A logic gate is a hardware component that controls the flow of signals.
Q5. What is an integrated circuit?
A5. An integrated circuit is a hardware component made up of silicon that contains lots of logic gates and other hardware components.
b What does a truth table show you?
A6. A truth table shows you all of the different possible inputs into a logic gate or logic diagram, and what the output is for each of the combinations.
Q7. If a logic circuit has 2 binary inputs, how many unique combinations of ones and zeros are there?
A7. 2 to the power 2 = 4.
Q8. If a logic circuit has 4 binary inputs, how many unique combinations of ones and zeros are there?
A8. 2 to the power 4 = 16.
Q9. If a logic circuit has X binary inputs, how many unique combinations of ones and zeros are there? (In other words, how do you work out the total number of unique combinations in any circuit diagram if you just know the total number of binary inputs into the diagram?)
A9. 2 to the power X.
Q10. How does an OR gate differ from an AND gate?
A10. In an AND gate, both inputs must be a one (TRUE) for there to be an output. In an OR gate, at least one input must be a one (TRUE) for there to be an output.