BCD Addition

BCD (Binary-Coded Decimal) is a system of representing decimal numbers using binary digits. In BCD, each decimal digit is represented by a 4-bit binary code. To add two BCD numbers, we follow the same rules as binary addition, but with a carry propagate from one decimal digit to another.

Given:
BCD number 1 = 1001
BCD number 2 = 0100

To add these two BCD numbers, we start from the rightmost digit and work our way to the left, adding each corresponding pair of digits, along with any carry generated from the previous addition.

Step 1:
Starting from the rightmost digit:
1 + 0 = 1 (No carry generated)

Step 2:
Moving to the next digit:
0 + 1 = 1 (No carry generated)

Step 3:
Moving to the next digit:
0 + 0 = 0 (No carry generated)

Step 4:
Moving to the next digit:
1 + 0 = 1 (No carry generated)

The addition of the two BCD numbers results in the sum:
1001 + 0100 = 1011

Conversion to decimal:
To convert the sum back to decimal, we group the bits into groups of 4 from right to left:
10 11

The decimal equivalent of the BCD number 1011 is 11.

Therefore, the correct answer is option 'C' - 00010011, which represents the decimal number 11.