Twos complement of 000101 – UGC NET Question

To find the 2's complement, we first take the 1's complement by inverting each bit and then add 1. For 000101, the 1's complement is 111010. Adding 1 to 111010 gives 111011. Hence, 111011 is the correct 2's complement.

Option A:
Option A, 111001, is not one increment above the 1's complement 111010 and therefore cannot be the 2's complement. Its last two bits do not reflect the required addition.

Option B:
Option B, 111010, is just the 1's complement without adding 1. Since 2's complement requires this extra step, stopping at 111010 is incomplete.

Option C:
Option C, 111000, differs from both the required 1's and 2's complement results. It effectively subtracts value rather than adding one to the inverted pattern.

Option D:
Option D is correct because it accurately follows the two-step process of bit inversion and addition of 1. This pattern is commonly used to represent negative numbers in binary arithmetic.