DE Unit 3 – Part B Short Notes (2 Marks Each)

1️⃣ What is a Multiplexer (MUX)?

English Answer:
Multiplexer = “Many to One” device.
It selects one of several data inputs and connects it to a single output line based on control (Select) inputs.

Tamil Answer:
பல inputs-லிருந்து ஒன்றை select செய்து output ஆக கொடுக்கும் combinational logic circuit ஆகும்.

2️⃣ Define Parity Checker.
English Answer:

A parity checker is used at the receiving end of data transmission to detect single bit errors by checking the parity bit.
Types: Even Parity Checker, Odd Parity Checker.

Tamil Answer:
Parity Checker என்பது பெறப்பட்ட information-ல் error உள்ளதா என்பதை check செய்யும் combinational logic circuit ஆகும்.

Types: Even Parity Checker, Odd Parity Checker.

3️⃣ Define Decoder.

English Answer:
A decoder converts binary information from n inputs to a maximum of 2ⁿ unique outputs.

Tamil Answer:
Decoder என்பது binary input ஐ பொறுத்து அதற்கேற்ப ஒரு output ஐ உருவாக்கும் digital circuit ஆகும்.

4️⃣ Define Demultiplexer (Demux).

English Answer:

A “One to Many” device that sends a single input signal to one of several outputs based on select lines. It is called a data distributor circuit.

Tamil Answer:
“One to Many” device ஆகும், இது select lines அடிப்படையில் ஒரு input signal-ஐ பல outputs-இல் ஏதேனும் ஒன்றிற்கு அனுப்பும் data distributor circuit ஆகும்.

5️⃣ Define Parity Generator.

English Answer:
A parity generator adds a parity bit to a data word to make the number of 1’s either even or odd.
Types: Even Parity and Odd Parity Generators.

Tamil Answer:

Parity Generator என்பது ஒரு data word-க்கு ஒரு parity bit சேர்த்து, அதில் உள்ள 1’s எண்ணிக்கை even அல்லது odd ஆக இருக்க செய்யும்.

Types: Even Parity and Odd Parity Generators.

6️⃣ Define Half Subtractor.

English Answer:
A Half Subtractor is a combinational circuit that performs subtraction of two bits.
Outputs: Difference (D = A ⊕ B), Borrow (B = A′ B).

Tamil Answer:
இரண்டு binary bits-ஐ subtraction செய்யும் combinational logic circuit ஆகும்.

Outputs: Difference (D = A ⊕ B), Borrow (B = A′ B).

7️⃣ Difference between MUX and DEMUX.

Feature	MUX	DEMUX
Function	Many → One	One → Many
Use	Data selection	Data distribution
Type	Data selector	Data distributor

8️⃣ Define Encoder.

English Answer:
An encoder converts 2ⁿ input signals into n output code signals.

Tamil Answer:
பல inputs-லிருந்து ஒன்றை code ஆக மாற்றும் combinational logic circuit ஆகும்.

9️⃣ Define Half Adder.

English Answer:
A Half Adder adds two binary bits and produces Sum and Carry.
Sum = A ⊕ B, Carry = A · B.

Tamil Answer:

இரண்டு binary numbers-ஐ addition செய்யும் combinational circuit ஆகும்.

Sum = A ⊕ B, Carry = A · B.

🔟 Applications of MUX.

• Communication systems (data transmission)
• Telephone networks
• Computer memory address selection
• Data transmission in satellites