# 03 - Logic Gates

1. Digital systems are said to be constructed by using logic gates. These gates are the AND, OR, _____, NAND, NOR, EXOR and EXNOR gates.

NOP

GATE X

GATE Y

NOT

2. Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using vacuum tubes, electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical el

FALSE

TRUE

3. Read the following excerpt and see if you can fill in the blanks.
```Learning tip about logic gates:
===============================
In a computer, we can also use a gate to control a flow and achieve
an end goal. We control the flow of an electric current as it goes
running around a circuit.
This gate in the world of digital electronics is known as a transistor
and can be in one of two states, on or off, or open or closed if you
like to think of it as a gate.
When a transistor is on, or open, then an electric current can flow through.
And when it’s off, then ____________________```

no current flows

no gates remain open

a single electrical signal gets through

several electrical signals get through

4. This excerpt explains how it all fits together. Fill in the blanks and be sure to read it all!
```Excerpt that explains how it all fits together
==================================================
When you string a bunch of these transistors together, then you
get what’s called a ____________, which lets you add, subtract,
multiply, and divide binary numbers in any way imaginable.
In a physical circuit,
these logic gates have:

Inputs.
=======
All logic gates require some kind of input value so that they
have numbers to compare. These figures come in the form of voltages. When
your input voltage is 0V, then it’s considered to be low, or 0. And when
you have a voltage of 5V as an input, then this is deemed to be high, or 1.

Outputs.
=========
Once a logic gate has a chance to process your input, it can then
make a decision on whether to open its gate or keep it closed. This output is
entirely determined by the type of logic gate you’re using, and some will only
open if you have two high voltages as an input, whereas others will only open
if you have a low voltage but not a high voltage as an input.```

Logic Gate

CPU

And Gate

Mega transistor

5. Modern day ______________________are mathematical powerhouses, stringing together a dizzying amount of logic gates with the help of transistors to perform calculations and process data

motherboards

RAM chips

integrated circuits

computers

6. An 'AND' gate requires two inputs of a '1' in order to get an output of a '1'. An example of this in plain english is:
`Learning note: Regardless of the logic gate we’re talking about, the inputs and outputs will break everything down to two binary numbers that make up digital electronics, 1 and 0.`

if someone does not knock on the door, do not open the door.

if someone knocks on the door or bangs on the door or rings the alarm, do not open the door

if someone rings the alarm or knocks, open the door

if someone rings the alarm and knocks, then open the door

7. Look at the image below and see if you can fill in the "?". What is the output?

1 because in an AND gate either input needs to be a 1

1 because in an AND gate both inputs need to be a 1 to get a 1

0 because in an AND gate either input needs to be a 1

0 because in an AND gate both inputs need to be 1 to get a 1, and in this case it isn't

8. In the following image we have an AND gate with two _____ A and B, and one _________

logic gates / output

inputs / output

outputs / input

logic gates / input

9. An '____' gate as shown in the image is requires either input A or B to be a 1 for the output to be 1.

NAND

OR

NOT

AND

10. A NOT gate, as shown, inverts signals. So if the input A is 1, the output would be:

1

2

0

Error

11. Most amazing laptops today have solid state drives. The magic gate behind SSDs is the ________

NOT

AND

OR

NAND

12. A NAND gate is a …..
```Watch the video if you're interested to find out more          #1
==============
AND - OR gate which is equal to an OR gate followed by a NOT gate.
The outputs of all NAND gates are low if any of the inputs are low

#2
===============
NOT-AND gate which is equal to an AND gate followed by a NOT gate.
The outputs of all NAND gates are high if any of the inputs are low```

Option #2

Option #1

Both of them are correct

Neither of them are correct

13. What 'gates' does the following circuit diagram include?

And, Not

And, Or, Not

And only

Or Only

14. What 'gates' does the following circuit diagram include?

Not Gates

And, Or Gates

This diagram has no gates in it whatsoever ….

Or Gates

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

FALSE

TRUE

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

FALSE

TRUE

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

TRUE

FALSE

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

TRUE

FALSE

19. How can you add, subtract, multiply, and divide using nothing but electric currents?

All of the above are true

It is not possible to do this - a human must get involved

Calculators and Computers use special registers on the Hard drive to achieve this

Calculators and computers do this using clever electronic circuits called logic gates

20. This logical way of comparing numbers to make decisions that produce either a yes or no, 1 or 0, true or false is called Boolean algebra after its discoverer, English mathematician George Boole (1815 - 1864)

False

True