# 15 Lecture

## CS302

### Midterm & Final Term Short Notes

A BCD adder is a combinational logic circuit that adds two Binary Coded Decimal (BCD) numbers and produces a BCD output. BCD is a system of representing numbers in which each digit is represented by a binary code. BCD adder circuits are used in

## Important Mcq's Midterm & Finalterm Prepration Past papers included

1. What is the purpose of a BCD adder circuit? A) To add two binary numbers B) To add two decimal numbers C) To add two BCD numbers D) To subtract two BCD numbers

1. Which type of logic gates are used in BCD adder circuit? A) AND gates B) OR gates C) XOR gates D) All of the above

1. How many bits are required to represent a single BCD digit? A) 2 B) 3 C) 4 D) 5

1. How many full adders are required to design a 4-bit BCD adder? A) 1 B) 2 C) 3 D) 4

1. Which input(s) of a BCD adder are applied to the carry-in of the first full adder? A) The least significant bit (LSB) of both inputs B) The most significant bit (MSB) of both inputs C) The carry-out of the previous stage and the LSB of the current stage input D) None of the above

1. What is the maximum sum that can be generated by a single BCD adder? A) 9 B) 10 C) 15 D) 16

1. What is the carry-out of a full adder when both inputs are 1? A) 0 B) 1 C) 2 D) Cannot be determined

1. Which type of multiplexer is used in BCD adder to select between the carry-in and sum output of the full adder? A) 2:1 B) 4:1 C) 8:1 D) 16:1

1. What is the purpose of the parity generator in BCD adder circuit? A) To check for errors in the input data B) To ensure that the output is a valid BCD number C) To generate a parity bit for error detection D) None of the above

1. What is the maximum number of BCD digits that can be added using an 8-bit BCD adder? A) 1 B) 2 C) 4 D) 8

## Subjective Short Notes Midterm & Finalterm Prepration Past papers included

1. What is BCD code? BCD stands for Binary Coded Decimal which is a coding scheme used to represent decimal numbers in binary form.

2. What is the purpose of BCD adder circuit? The purpose of a BCD adder circuit is to add two BCD numbers and provide the output in BCD format.

3. How many digits can a BCD adder circuit handle? A BCD adder circuit can handle up to four digits in each BCD number.

4. What is the significance of carry propagation in BCD adder? Carry propagation is important in BCD adder as it carries the carry from one digit to the next when the sum of two digits exceeds nine.

5. What is the difference between a BCD adder and a binary adder? A BCD adder operates on binary coded decimal numbers, while a binary adder operates on binary numbers.

6. What is a half adder? A half adder is a combinational circuit that adds two single-bit binary numbers and produces a sum and carry bit as output.

7. What is a full adder? A full adder is a combinational circuit that adds three single-bit binary numbers and produces a sum and carry bit as output.