Digital Electronics/ 2-valued Boolean algebra and it’s theorem in Digital Logic with easy explanation.

Digital Electronics/ 2-valued Boolean algebra and it’s theorem in Digital Logic with easy explanation.

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 2-Valued Boolean Algebra & Its Theorems in Digital Logic

🔹 What is 2-Valued Boolean Algebra?

Boolean Algebra is a mathematical system used in digital electronics where variables take only two values:
✅ 0 (False / LOW)
✅ 1 (True / HIGH)



All digital circuits (AND, OR, NOT gates) use Boolean algebra to simplify logic expressions.

 Basic Boolean Operations

1️⃣ AND Operation (⋅)

  • Symbol: A⋅BA \cdot B or ABAB
  • Truth Table:
    A B A ⋅ B
    0 0 0
    0 1 0
    1 0 0
    1 1 1
  • Example: 1⋅1=1,1 \cdot 1 = 1, 0⋅1=00 \cdot 1 = 0

2️⃣ OR Operation (+)

  • Symbol: A+BA + B
  • Truth Table:
    A B A + B
    0 0 0
    0 1 1
    1 0 1
    1 1 1
  • Example: 1+0=1,1 + 0 = 1, 0+0=00 + 0 = 0

3️⃣ NOT Operation (¬ or ‘)

  • Symbol: A′A’ or ¬A\neg A
  • Truth Table:
    A A’
    0 1
    1 0
  • Example: 1′=0,1′ = 0, 0′=10′ = 1

 Boolean Algebra Theorems

These theorems help in simplifying logic circuits.

1️⃣ Identity Law

  • A+0=AA + 0 = A
  • A⋅1=AA \cdot 1 = A

2️⃣ Null Law

  • A+1=1A + 1 = 1
  • A⋅0=0A \cdot 0 = 0

3️⃣ Idempotent Law

  • A+A=AA + A = A
  • A⋅A=AA \cdot A = A

4️⃣ Involution Law

  • (A′)′=A(A’)’ = A

5️⃣ Complement Law

  • A+A′=1A + A’ = 1
  • A⋅A′=0A \cdot A’ = 0

6️⃣ Distributive Law

  • A⋅(B+C)=(A⋅B)+(A⋅C)A \cdot (B + C) = (A \cdot B) + (A \cdot C)
  • A+(B⋅C)=(A+B)⋅(A+C)A + (B \cdot C) = (A + B) \cdot (A + C)

7️⃣ Absorption Law

  • A+(A⋅B)=AA + (A \cdot B) = A
  • A⋅(A+B)=AA \cdot (A + B) = A

8️⃣ De Morgan’s Theorems

  • (A⋅B)′=A′+B′(A \cdot B)’ = A’ + B’
  • (A+B)′=A′⋅B′(A + B)’ = A’ \cdot B’

 Example: Simplify the Expression

Expression: A+(A⋅B)A + (A \cdot B)
Using Absorption Law:
A+(A⋅B)=AA + (A \cdot B) = A

So, instead of using a circuit with AND and OR gates, we can directly use A, saving hardware.

 Summary

✔ Boolean Algebra is used in Digital Logic & Circuits.
✔ 2-Valued Boolean Algebra uses only 0 & 1.
✔ Boolean Theorems help simplify logic circuits.

Would you like circuit diagrams or more solved examples?

Digital Electronics/ 2-valued Boolean algebra and it’s theorem in Digital Logic with easy explanation.

01. Boolean Algebra and Logic Gates.pmd

UNIT-II Boolean algebra and Logic Gates

Boolean Algebra and Logic Gate

Here’s a clear and easy-to-understand explanation of 2-Valued Boolean Algebra and its theorems in Digital Electronics / Digital Logic, ideal for students of B.Tech, GATE, or competitive exams.


💡 What is 2-Valued Boolean Algebra?

Boolean Algebra is a mathematical structure used to perform operations on binary variables (0 and 1).

In 2-valued Boolean algebra, each variable has only two possible values:

  • 0False/Low

  • 1True/High

It forms the backbone of digital circuits and logic design.


⚙️ Basic Boolean Operations

Operation Symbol Meaning Example
AND · or ∧ Multiply 1·1 = 1
OR + Add 1+0 = 1
NOT ¬ or ‘ Invert ¬1 = 0

📘 Basic Boolean Theorems / Laws

✅ 1. Identity Laws

  • A + 0 = A

  • A · 1 = A

✅ 2. Null Laws

  • A + 1 = 1

  • A · 0 = 0

✅ 3. Idempotent Laws

  • A + A = A

  • A · A = A

✅ 4. Complement Laws

  • A + A’ = 1

  • A · A’ = 0

✅ 5. Double Negation Law

  • (A’)’ = A


✅ 6. Commutative Laws

  • A + B = B + A

  • A · B = B · A

✅ 7. Associative Laws

  • A + (B + C) = (A + B) + C

  • A · (B · C) = (A · B) · C

✅ 8. Distributive Laws

  • A · (B + C) = A·B + A·C

  • A + (B · C) = (A + B) · (A + C)


✅ 9. Absorption Laws

  • A + A·B = A

  • A · (A + B) = A

✅ 10. De Morgan’s Theorems

  • (A · B)’ = A’ + B’

  • (A + B)’ = A’ · B’

💡 These are extremely important in circuit simplification.


🧠 Tip to Remember

Use truth tables to verify the theorems. For example:

Theorem: A + A’ = 1

A A’ A + A’
0 1 1
1 0 1

✅ Verified!


🔧 Real-Life Application

All logic gates (AND, OR, NOT, NAND, NOR, XOR) are physical implementations of Boolean operations.
Using these laws:

  • We simplify digital circuits

  • We design efficient hardware

  • We minimize logic expressions


📝 Summary Cheat-Sheet

Law/Rule Name Expression(s)
Identity A + 0 = A, A · 1 = A
Null A + 1 = 1, A · 0 = 0
Idempotent A + A = A, A · A = A
Complement A + A’ = 1, A · A’ = 0
Double Negation (A’)’ = A
Commutative A + B = B + A, A · B = B · A
Associative A + (B + C) = (A + B) + C
Distributive A · (B + C) = A·B + A·C
Absorption A + A·B = A
De Morgan’s Laws (A · B)’ = A’ + B’, (A + B)’ = A’ · B’

📥 Want a PDF or Video Explanation?

I can generate:

  • A 1-page PDF summary (perfect for revision)

  • A video script for YouTube/Tutorial

  • A truth table practice worksheet

Just let me know what format you prefer!

Digital Electronics/ 2-valued Boolean algebra and it’s theorem in Digital Logic with easy explanation.

DIGITAL ELECTRONICS BOOLEAN ALGEBRA

Digital Electronics (18EC32) Notes



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