Question

The binary subtraction of 0 – 0 =?

(a) Difference = 0, borrow = 0

(b) Difference = 1, borrow = 0

(c) Difference = 1, borrow = 1

(d) Difference = 0, borrow = 1

The question was posed to me by my college director while I was bunking the class.

I want to ask this question from 4-Bit Parallel Adder/Subtractor topic in division Arithmetic Circuits of Digital Circuits

Answer 1

Correct option is (a) Difference = 0, borrow = 0

Easiest explanation: The binary subtraction of 0 – 0 = 0. Thus, it’s difference is 0 as well as it’s borrow.