# 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.```

bulbs

gates

CPUs

mates

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

FALSE

3. The functionality of each gate can be described using a ________________

boolean multiplication law

truth table

alegebraic expression

logic gate correlation

4. The following gate is an '_______' gate. OR

NAND

NOT

AND

5. The following gate is an '_______' gate. OR

NAND

NOT

AND

6. The following gate is an '_______' gate. NOT

OR

AND

NAND

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

0

1

2

3

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

at least two

at least one

none

all

9. 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)

converted

negative

inverted

positive

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

TRUE

FALSE

11. 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```

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

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

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

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

12. If the input is 0 and it goes through a NOT gate, the output would also be 0

TRUE

FALSE

13. To get an output of 1 using an AND gate, it would be necessary to have a 1 and a 1 (two ones)

TRUE

FALSE

14. An OR gate would produce an output of 1 if the input is 0 and 0.

FALSE

TRUE

15. It is the OR gate that is shaped like a triangle.

FALSE

TRUE