Logic

Question 1

What are logic gates?

Answer 1

Special circuits built into computer chips. They receive binary data, apply a Boolean operator then output a binary result.

Question 2

What do logic diagrams show?

Answer 2

logic gates and circuits

Question 3

What is the NOT gate?

Answer 3

• take a single input and give a single output
• the output is always opposite to the input
• e.g. 1 = 0 and 0 = 1

Question 4

What is an AND gate?

Answer 4

• take two inputs and give one output

- if both inputs are 1 the output is 1 otherwise the output is 0

Question 5

What is an OR gate?

Answer 5

• takes two inputs and give one output

- if one or more inputs are 1 then the output is 1 otherwise the output is 0.

Question 6

What’s the notation of a AND gate?

Answer 6

A ^ B

Question 7

What’s the notation of a OR gate?

Answer 7

A V B

Question 8

What’s the notation of a NOT gate?

Answer 8

line across to the right to go down a little

Question 9

What do multiple logic gates do when added to the same logic circuit?

Answer 9

Carry out different operations

Question 10

How can you work out the truth tables for multiple logic gates?

Answer 10

• working through each gate in order

- for every input combination follow them through each gate step-by-step then write down the output.

Question 11

How can circuits be written as logical statements?

Answer 11

Using brackets and the terms AND, OR and NOT

e. g. NOT(A AND B)
- operators in brackets should be completed first

Question 12

What are two-level logic circuits?

Answer 12

Require inputs to pass through a maximum of two logic gates to reach the output.