BONAFIDE CERTIFICATE

Certified to be the bonafide work done by Miss

HELNA CHARLY of class XI-D in the United Indian

School, Kuwait during the academic year 2024-

2025.
 ACKNOWLEGDEMENT

First and foremost, I would like to express my

gratitude for the golden opportunity to do this
wonderful project on Logic Gates.

It helped me to learn a lot of new information

during the course of completion of the project.

Secondly, I would like to extend my sincere thanks

of gratitude to my teacher Mrs. Mahita
Manoharan for her able guidance and support in
completing my Project.

Last but not least, I would also like to express my

heartfelt thanks towards my parents for their
valuable suggestions and to all those who
supported and guided me in finalizing project.
 CONTENTS
Sr.no Title Page no.
1 Introduction 1

2 Principle 2

3 The AND Gate 3

4 The OR Gate 6

5 The NOT Gate 7

6 The NOR Gate 8

7 The NAND Gate 9

8 The EX-OR Gate 10

9 The EX-NOR 11
Gate
10 Conclusion 12

11 Bibliography 13
 Introduction
GATE: - A gate is defined as a digital circuit which
follows some logical relationship between the input and
output voltages. It is a digital circuit which either allows
a signal to pass through or stop it.
The logic gates are building blocks at digital
electronics. They are used in digital electronics to
change one voltage level into another according to some
logic statement relating to them.

Truth Table: - A logic gate may have one or more than

one inputs, but it has only one output. The relationship
between the possible values of input and output
voltages are expressed in the form of a table called truth
table.
Truth table of a logic gate is a table that shows all
The inputs and outputs that are possible for the logic
gates.

Boolean algebra: - The algebra which is based on

binary nature of the logic gates.

Boolean Expressions: - They are the logical statement

which are followed by logical gates.

- Making of logic gates was started by

binary numbers.

- Logic gates can also store information.

1
 Principle
Any Boolean algebraic operation can be associated
with the input and output, which represents the
statement of Boolean algebra. Although these circuits
may be complex, they may all be constructed from
three basic
Devices like a P-N junction diode, a resistance and an
N-P- N transistor.
We have three different type of logic gates and they
are the AND gate, the OR gate and the NOT gate.

LOGICAL STATEMENTS
1 0
High Low
Positive Negative
On Off
Close Open
Conducting Non-Conducting
Right Wrong
True False
Yes No
The AND Gate
Aim:
TO DESIGN AND STIMULATE THE AND
GATE CIRCUIT.
Components:
Two ideal p-n junction diode (D1 and D2) and resistance R.

Theory :
The AND Gate: - It is a device that combines A with
B to give Y as the result. The AND gate has two or
more inputs and one o u t p u t . In Boolean algebra,
multiplication sign is referred as the AND.
The Boolean expression: A.B=Y o r A X B=Y
This indicates that Y equals to A and B.
Construction:

An AND gate can be realized by the electronic

circuit, making use of two diodes D1 and D2.
The resistance R is connected to the positive
terminal of a 5V battery permanently.

Here the negative terminal of the battery is

grounded and corresponds to the 0 level, and the
positive terminal of the battery corresponds to the
level 1. The output Y is the voltage at C with
respect to earth.
The following conclusion can b e easily drawn from
the working of this circuit:
(i) If the switch A and B are kept open (A=0,
B=0), then bulb does not glow, hence Y=0.
(ii) If switch A is kept closed and B is kept
open (A=1, B=0), then bulb does not glow,
hence Y=0.
(iii) If switch A is kept open and B is kept
closed (A=0, B=1), then bulb does not
glow, hence Y=0.
(iv) If both switch A and B are kept closed
(A=1, B=1), then bulb glows, hence Y=1.

TRUTH TABLE:
Input A Input B OUTPUT
0 0 0
0 1 0
1 0 0
1 1 1
The OR Gate
The OR Gate: - It is a device that combines A and B
to give Y as the result. The OR gate has two or more
inputs and one output. In Boolean algebra, addition
symbol (+), is referred as the OR.

The Boolean expression: A+B=Y

This indicates that Y equals to A or B.

TRUTH TABLE:
Input A Input B OUTPUT
0 0 0
0 1 0
1 0 0
1 1 1
The NOT Gate
It is a device that inverts the inputs. The NOT has
one input and has one o u t p u t . In Boolean algebra,
bar symbol is referred as the NOT.
The Boolean expression:

This indicates that Y is not equal to A.

TRUTH TABLE:
Input A OUTPUT Y
0 1
1 0
The NOR Gate
The NOR gate is a key component in digital
electronics and logic design. It outputs a high (1)
only when all its inputs are low (0), making it the
complement of the OR gate.
In Boolean expression, the NOR gate is expressed
as:

TRUTH TABLE:
Input A Input B OUTPUT
0 0 1
0 1 0
1 0 0
1 1 0
The NAND Gate
NAND gate represents a fundamental logical
operation that combines the AND operation with a
NOT operation. Which is the complement of the
logical AND operation.
The NAND gate is a universal gate, meaning that
it can be used to construct any other logic gate or
function.
It outputs true (1) only when at least one of its
inputs is false (0). If all its inputs are true (1), the
output will be false (0).
In Boolean expression, the NAND gate is expressed
as: Y=A B

TRUTH TABLE:
Input A Input B OUTPUT
0 0 1
0 1 1
1 0 1
1 1 0
The X-OR Gate
The XOR (Exclusive OR) gate is a
fundamental logic gate that performs an
exclusive disjunction.
The output is true (1) if and only if one
of its inputs is true (1), and the other is
false (0). If both inputs are either true (1)
or false (0), the output is false (0).
In Boolean expression, the EX-OR g a t e is
expressed as: Y=A B

TRUTH TABLE:
Input A Input B OUTPUT
0 0 0
0 1 1
1 0 1
1 1 0
The X-NOR Gate
The XNOR gate, or Exclusive NOR gate,
is a fundamental logic gate in Boolean
algebra that performs a logical exclusive
NOR operation. It is the complement of
the XOR (Exclusive OR) gate.

In Boolean expression, the EX-NOR gate is

expressed as

TRUTH TABLE:
Input A Input B OUTPUT
0 0 1
0 1 0
1 0 0
1 1 1
Conclusion
Logic gates are used to develop many IC
circuits or microchips in today’s modern
world.
NAND gate and NOR gate are known as
universal gates because we can construct
all the three basic gates using NAND &
NOR gates.

Without logic gates, electronic world

would be nearly incomplete!
THANK YOU
Bibliography
This project would be nearly incomplete if
I had not used the information given in
the following websites.
 Google
 Wikipedia
 NCERT.com