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03 - Logic Gates

 1. 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

  a single electronic signal is let through

  no gates remain open

  the current flows

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

  motherboards

  RAM chips

  computers

  integrated circuits

 4. 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 rings the alarm and knocks, then 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

 5. Look at the image below and see if you can fill in the "?". What is the output?
logicgates_question8.png

  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

 6. An '____' gate as shown in the image requires either input A or B to be a 1 for the output to be 1.
logicgates_question10.png

  NAND

  AND

  NOT

  OR

 7. What 'gates' does the following circuit diagram include?
logicgates_question14.png

  And, Not

  Or Only

  And, Or, Not

  And only

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

  NOT

  GATE X

  NOP

  GATE Y

 9. For the logic gate equation: P = A OR B, we are saying that ___________________

  ....the output is always 0 because this is an AND gate

  ....the output is always equal to the input B

  ...the output is equal to A OR B

  ....the output is equal to A AND B

 10. 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.

  And Gate

  Mega transistor

  CPU

  Logic Gate

 11. In the following image we have an AND gate with two _____ A and B, and one _________
logicgates_question9.png

  inputs / output

  logic gates / output

  outputs / input

  logic gates / input

 12. A NOT gate, as shown, inverts signals. So if the input A is 1, the output would be:
logicgates_question11.png

  0

  Error

  2

  1

 13. Most amazing laptops today have solid state drives. The magic gate behind SSDs is the ________
logicgates_question12.png

  NAND

  OR

  NOT

  AND

 14. 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
logicgates_question13.gif

  Option #1

  Neither of them are correct

  Option #2

  Both of them are correct

 15. The following logic circuit diagram contains a combination of 'NOT' and 'AND' gates.
logicgates_question15.png

  True

  False