GATE 2002

Question 21

In 2’s complement addition, overflow

A	is flagged whenever there is carry from sign bit addition
B	cannot occur when a positive value is added to a negative value
C	is flagged when the carries from sign bit and previous bit match
D	None of the above

Question 21 Explanation:

The left most bit of positive value is zero. And left most bit for negative value is one. The value of 0+1 becomes 1. Then overflow never occurs.

Correct Answer: B

Question 21 Explanation:

The left most bit of positive value is zero. And left most bit for negative value is one. The value of 0+1 becomes 1. Then overflow never occurs.