This document discusses logic gates, including their introduction, types, truth tables, and applications. It describes the basic AND, OR, NOT, NAND, and NOR gates and provides their truth tables. Logic gates are elementary building blocks of digital circuits that have binary inputs and outputs. They are used to build circuits for applications like burglar alarms and fire alarms.

1. PRESENTATION
Moazamah Rubab

2. LOGIC GATES
 Introduction
 Types
 Truth Tables
 Applications

3. INTRODUTION
What are logic gates?
A logic gate is an elementary building
block of a digital circuit. Most logic gates
have two inputs and one output. At any
given moment, every terminal is in one of
the two binaryconditions low (0)
or high (1), represented by different
voltage levels.

4. Types
 AND GATE
 OR GATE
 NOT GATE
 NAND GATE
 NOR GATE

5. AND GATE
 For a 2-input AND gate, the output Q is true if BOTH
input A "AND" input B are both true, giving the
Boolean Expression of: ( Q = A .B ).
Symbol Truth Table
A B Q
0 0 0
0 1 0
1 0 0
1 1 1
Read as A AND B gives Q

6. OR GATE
 For a 2-input OR gate, the output Q is true if EITHER
input A "OR" input B is true, giving the Boolean
Expression of: ( Q = A + B ).
Symbol Truth Table
A B Q
0 0 0
0 1 1
1 0 1
1 1 1
Read as A OR B gives Q

7. NOT GATE
 For a single input NOT gate, the output Q is ONLY
true when the input is "NOT" true, the output is the
inverse or complement of the input giving the
Boolean Expression of: ( Q = NOT A ).This is also
shown as
Symbol Truth Table
A Q
0 1
1 0
Read as inverse of A gives Q

8. NAND GATE
 For a 2-input NAND gate, the output Q is true if
BOTH input A and input B are NOT true, giving the
Boolean Expression of: ( Q = not(A .B) ).This is also
shown as
Symbol Truth Table
A B Q
0 0 1
0 1 1
1 0 1
1 1 0
Read as A AND B gives NOT-Q

9. NOR GATE
 For a 2-input NOR gate, the output Q is true if BOTH
input A and input B are NOT true, giving the
Boolean Expression of: ( Q = not(A + B) ). This is also
shown as
Symbol Truth Table
A B Q
0 0 1
0 1 0
1 0 0
1 1 0
Read as A OR B gives NOT-Q

10. The following Truth Table describes the logical
functions of the 2-input logic gates.
Inputs Truth Table Outputs for each Gate
A B AND
NAN
D
OR NOR
0 0 0 1 0 1
0 1 0 1 1 0
1 0 0 1 1 0
1 1 1 0 1 0

11. APPLICATIONS
 Logic gates are used in:
 Burglar Alarm
 Fire Alarm etc.

12. THANK YOU!
