if u want to represent in $1$ bit, then sign bit not shown, only 1 will be in result

0

For 0 - 1

Using 2's complement in we could represent only -1 and 0 when no of bits=1.

The 2's complement of 1 is 1 and when we add 0 with 2's complement of 1 then we get1 as the answer and no carry and that is why we have a borrow of 1??

In Single Precision floating point number when E=0 and M not equals to 0 it represents a fractional form..(BiAS=+127) when writing the decimal form why do we right (-1)^S * (1.M) * 2^(-126) instead of (-1)^S * (1.M) * 2^(-127)??