Answer: there is an overflow
Step-by-step explanation:
Here using 4-bit signed fields to store the addition value.
0111 + 0101 = 1100
In above addition the MSB is reserved for sign.
If MSB is 0 means the number is positive.
If MSB is 1 means the number is negative.
The first number 0111 has MSB 0 means it is a positive number.
The second number 0101 has MSB 0 means it is also a positive number.
But after addition the result obtained is 1100 which MSB is 1 indicating the
result is negative number.
How can it be possible to add two positive numbers and get a negative number as result.
This type of situation is called overflow situation.
It is used for error detection purpose.
therefore there is an overflow