**Digital Circuits Questions and Answers – 1’s, 2’s, 9’s & 10’s Complements – 2**

This set of Digital Electronic Circuits Interview Questions and Answers focuses on “1’s,2’s,9’s & 10’s Complements-2”.

**1. If the number of bits in the sum exceeds the number of bits in each added numbers, it results in _________**

a) Successor

b) Overflow

c) Underflow

d) Predecessor

**Answer:**b

**Explanation:**If the number of bits in the sum exceeds the number of bits in each added numbers, it results in overflow and is also known as excess-one. In case of any arithmetic operation, if the result has less number of bits than the operands, then it is known as underflow condition.

**2. An overflow is a _________**

a) Hardware problem

b) Software problem

c) User input problem

d) Input Output Error

**Answer**: b

**Explanation:**An overflow is a software problem which occurs when the processor cannot handle the result properly when it produces an out of the range output.

**3. An overflow occurs in _________**

a) MSD position

b) LSD position

c) Middle position

d) Signed Bit

**Answer:**a

**Explanation:**An overflow occurs at Most Significant Digit position. It occurs when the processor cannot handle the result properly when it produces an out of the range output.

**4. Logic circuitry is used to detect _________**

a) Underflow

b) MSD

c) Overflow

d) LSD

**Answer:**c

**Explanation:**To check the overflow logic circuitry is used in each case. Overflow occurs when the processor cannot handle the result properly when it produces an out of the range output.

**5. 1’s complement can be easily obtained by using _________**

a) Comparator

b) Inverter

c) Adder

d) Subtractor

**Answer:**b

**Explanation:**With the help of inverter the 1’s complement is easily obtained. Since, during the operation of 1’s complement 1 is converted into 0 and vice-versa and this is well suited for the inverter.

**6. The advantage of 2’s complement system is that _________**

a) Only one arithmetic operation is required

b) Two arithmetic operations are required

c) No arithmetic operations are required

d) Different Arithmetic operations are required

**Answer:**a

**Explanation:**The advantage of 2’s complement is that only one arithmetic operation is required for 2’s complement’s operation and that is only addition. Just by adding a 1 bit to 1’s complement, we get 2’s complement.

**7. The 1’s complements requires _________**

a) One operation

b) Two operations

c) Three operations

d) Combined Operations

**Answer:**a

**Explanation:**Only one operation is required for 1’s complement operation. This includes only inversion of 1’s to 0’s and 0’s to 1’s.

**8. Which one is used for logical manipulations?**

a) 2’s complement

b) 9’s complement

c) 1’s complement

d) 10’s complement

**Answer:**c

**Explanation:**For logical manipulations 1’s complement is used, as all logical operations take place with binary numbers.

**9. For arithmetic operations only _________**

a) 1’s complement is used

b) 2’s complement

c) 10’s complement

d) 9’s complement

**Answer:**b

**Explanation:**Only 2’s complement is used for arithmetic operations, as it is more fast.

**10. The addition of +19 and +43 results as _________ in 2’s complement system.**

a) 11001010

b) 101011010

c) 00101010

d) 0111110

**Answer:** d

**Explanation:** The decimal numbers are converted to their respective binary equivalent and then the binary addition rules are applied.

**« Prev – Digital Circuits Questions and Answers – 1’s, 2’s, 9’s & 10’s Complements – 1**

**» Next – Digital Circuits Questions and Answers – Binary Coded Decimal(BCD)**