# 02 - Truth tables and logic circuits

1. The concept may be confusing at first but all digital circuits are created using a combination of logic _______________
```Learning note:
==============
>>Electronic gates require a power supply.

>>Gate INPUTS are driven by voltages having two nominal values, e.g.
0V and 5V representing logic 0 and logic 1 respectively.

>>The OUTPUT of a gate provides two nominal values of voltage only,
e.g. 0V and 5V representing logic 0 and logic 1 respectively.

>>In general, there is only one output to a logic gate except in some
special cases.There is always a time delay between an input being
applied and the output responding.```

mates

CPUs

gates

bulbs

2. The functionality of each gate can be described using a ________________
```The structure used to represent the boolean expression
of a logic gate function is commonly called a ___________.

A logic gate ____________shows each possible input combination
to the gate or circuit with the resultant output depending upon
the combination of these input(s).
```

mathematical formula

truth table

logical deduction using english statements

binary tree

3. The following gate is an '_______' gate.

AND

NAND

NOT

OR

4. The NOT gate is an electrical circuit that produces an _______ version of the input as the output. (e.g. a 1 will be a 0)

negative

inverted

positive

converted

5. A truth table can show the operations (with inputs and outputs) of any given gates. The following shows the truth table for the ________
```2 Input truth table for an ____gate
======================
A      B      Output
------------------------
0       0            0
0       1            0                                   1       0            0
1       1            1```

This truth table is incorrect and doesn't describe any gate

Or Gate because when either A or B inputs are 1 the output is 1

NOT Gate - because the output is always the inversion (opposite) of what is in A or B

And Gate because both inputs (A and B) need to be 1 in order for the output to be 1

6. Digital systems are said to be constructed by using logic gates. These gates are the AND, OR, NOT, NAND, NOR, EXOR and EXNOR gates.

FALSE

TRUE

7. The following gate is an '_______' gate.

NOT

OR

NAND

AND

8. The following gate is an '_______' gate.

AND

OR

NAND

NOT

9. The following gate is an '_______' gate.

NOT

OR

NAND

AND

10. The AND gate is an electrical circuit that gives an output of ____ only if all of its inputs are also _____.

1

0

3

2

11. The OR gate is an electrical circuit that gives an output of a 1 if_______________ of its inputs are a 1.

none

at least two

all

at least one

12. If the input into a NOT gate is a 0 the output will also be a 0.

FALSE

TRUE

13. Operations carried out by a NOT gate are also known as:

reverting

oppositing

inverting

opposing

14. A logic gate in which the output is zero for inputs in which one input is one and other input is zero is likely to be:

a FOR gate

a NOT gate

an OR gate

an AND gate

15. This is a table used to show possible combination of inputs for a specific output

Truth Table

Gate Table

False Table

Logic Table