Adder Circuit can be used as a Subtractor circuit by using _________.

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RRB ALP Electronics Mechanic 23 Jan 2019 Official Paper (Shift 3)

Answer 1

To use an Adder circuit as a Subtractor circuit, we can make use of what is known as the "2's complement" method.
This method involves taking the input number to be subtracted and finding its 2's complement.
The 2's complement of a number is obtained by inverting all the bits (changing 0's to 1's and 1's to 0's) and adding 1 to the result.
Once we have the 2's complement of the number to be subtracted, we can simply add it to the other input number using the Adder circuit.
The result will be the difference between the two numbers, just as in a Subtractor circuit.
For example, let's say we want to subtract 5 from 10 using an Adder circuit. The binary representation of 5 is 0101. To find its 2's complement, we invert all the bits to get 1010, and then add 1 to get 1011.
So, we can add 1011 to the binary representation of 10 (1010) using the Adder circuit to get the binary representation of 5 (0101), which is the difference between 10 and 5.