A Level Computer Science OCR Practice Exam

What does flipping the binary digits mean in the context of Two's Complement?

1. Changing 0s to 1s and 1s to 0s

2. Reversing the order of the digits

3. Adding a sign bit

4. Calculating the magnitude

The correct answer is: Changing 0s to 1s and 1s to 0s

Flipping the binary digits in the context of Two's Complement refers specifically to changing all the 0s to 1s and all the 1s to 0s, which is a fundamental step in the process of finding the Two's Complement representation of a negative number. This operation creates the one's complement of the binary number. In Two's Complement, once you've flipped the binary digits, the next step is to add 1 to the resulting binary number to obtain the final Two's Complement representation. This method effectively allows the representation of negative numbers in binary form, making it a vital technique in computer systems. The other options do not align with the concept of flipping binary digits in Two's Complement. Reversing the order of the digits changes the sequence but does not contribute to the value represented. Adding a sign bit pertains to the indication of whether a number is positive or negative but does not involve flipping the digits. Calculating the magnitude relates to determining the size of a number but is not directly pertained to the operation of flipping binary digits.