Explanation
The correct option is 1. -45.
Explanation:
The given 8-bit binary number is:
Binary Number=11010011
In signed number representation using two's complement, the Most Significant Bit (MSB), which is the leftmost bit, acts as the sign bit:
If MSB=0, the number is positive, and its value is calculated directly from its binary form.
If MSB=1, the number is negative. To find its decimal magnitude, we must find its two's complement configuration.
Since the leftmost bit here is 1, the number is negative.
Method 1: Using the Weight of the MSB
In an 8-bit signed representation, the positional weights of the bits are given as:
−27, 26, 25, 24, 23, 22, 21, 20
Now, map the given binary string 11010011 onto these weights:
Bit Position | 7 (MSB) | 6 | 5 | 4 | 3 | 2 | 1 | 0 (LSB) |
Weight | −27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 |
Value | −128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
Given Bit | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 1 |
Multiply each bit by its corresponding weight and sum them up:
Decimal Value=(1×−128)+(1×64)+(0×32)+(1×16)+(0×8)+(0×4)+(1×2)+(1×1)
Decimal Value=−128+64+0+16+0+0+2+1
Decimal Value=−128+83
Decimal Value=−45