# Computer Fundamentals Questions and Answers – The Output Unit

This set of Computer Fundamentals Interview Questions and Answers focuses on “The Output Unit”.

# Computer Fundamentals Questions and Answers – The Arithmetic & Logic Unit

This set of Computer Fundamentals Multiple Choice Questions & Answers (MCQs) focuses on “The Arithmetic & Logic Unit”.

1. The ‘heart’ of the processor which performs many different operations _____________
a) Arithmetic and logic unit
b) Motherboard
c) Control Unit
d) Memory

Explanation: The Arithmetic and logic unit performs all the basic operations of the computer system. It performs all the arithmetic(+,-,*,/,etc) as well as the logical operations( AND, OR, NOT, etc.).

2. ALU is the place where the actual executions of instructions take place during the processing operation.
a) True
b) False

Explanation: ALU is a combinational electronic circuit which basically performs all the logical or the bitwise operations and the arithmetic operations. Therefore, it is the place where the actual executions of instructions take place.

3. Which of the following is not a bitwise operator?
a) |
b) ^
c) .
d) <<

Explanation: All except the dot(.) operator are bitwise operators.
| : Bitwise OR
^ : Bitwise XOR
<< : Shift Left

4. The sign magnitude representation of -1 is __________
a) 0001
b) 1110
c) 1000
d) 1001

Explanation: The first leftmost bit i.e. the most significant bit in the sign magnitude represents if the number is positive or negative. If the MSB is 1, the number is negative else if it is 0, the number is positive. Here, +1=0001 and for -1=1001.

5. IEEE stands for ___________
a) Instantaneous Electrical Engineering
b) Institute of Emerging Electrical Engineers
c) Institute of Emerging Electronic Engineers
d) Institute of Electrical and electronics engineers

Explanation: The IEEE is an organization of professionals in the field of electronics and electrical engineering. IEEE has given certain standards of its own which are followed in the field of computer science and electrical engineering.

6. The ALU gives the output of the operations and the output is stored in the ________
a) Memory Devices
b) Registers
c) Flags
d) Output Unit

Explanation: Any output generated by the ALU gets stored in the registers. The registers are the temporary memory locations within the processor that are connected by signal paths to the CPU.

7. The process of division on memory spaces is called ______________
a) Paging
b) Segmentation
c) Bifurcation
d) Dynamic Division

Explanation: The memory space is divided into segments of dynamic size. The programmer is aware of the segmentation and can reallocate the segments accordingly.

8. Number of bits in ALU is _________
a) 4
b) 8
c) 16
d) 2

Explanation: Arithmetic and Logic Unit consists of 16bits. They perform certain Arithmetic and bitwise operations (add, subtract, AND, OR, XOR, Increment, decrement, shift).

9. Which flag indicates the number of 1 bit that results from an operation?
a) Zero
b) Parity
c) Auxiliary
d) Carry

Explanation: The parity flag indicates the number of 1 bit in any operation. The resultant bit is called the parity bit. The main aim of the parity bit is to check for errors.

10. The bitwise complement of 0 is ___________
a) 00000001
b) 10000000
c) 11111111
d) 11111110

Explanation: Bitwise complement is basically used to convert all the 0 digits to 1 and the 1s to 0s.
So, for 0 = 00000000(in 8-bits) ::: 11111111(1s complement). The bitwise complement is often referred to as the 1s complement.

# Computer Fundamentals Questions and Answers – The Control Unit

This set of Computer Fundamentals Multiple Choice Questions & Answers (MCQs) focuses on “The Control Unit”.

1. ____________ is the raw material used as input and __________ is the processed data obtained as output of data processing.
a) Data, Instructions
b) Instructions, Program
c) Data, Program
d) Program, Code

Explanation: Data can be assumed as a raw material which, in turns after processing gives the desired output in the form of instructions. Further, a set of ordered and meaningful instructions is known as a program.

2. Which of the following is not a characteristic of a computer?
a) Diligence
b) I.Q.
c) Accuracy
d) Versatility

Explanation: The Computer system has no I.Q. of its own. It does only what it is programmed to do. It cannot take decisions of its own.
A computer is diligent because it can work continuously for hours without getting any errors or without getting grumbled.
The accuracy of a computer is consistently high and its level of accuracy depends on its design. A computer can perform any task if, it can be broken down into a series of logical steps. Therefore, a computer is versatile.

3. Fill in the blank in the diagram. a) Input Unit
b) Memory Unit
c) Control Unit
d) I/O Unit

Explanation: The control unit manages and coordinates the operations of a computer system. The ALU is responsible for performing all the arithmetic and bitwise operations . Therefore, both these units combine to form the brain of the computer ,which is the central processing unit.

4. The part of a processor which contains hardware necessary to perform all the operations required by a computer:
a) Data path
b) Controller
c) Registers
d) Cache

Explanation: A processor is a part of the computer which does all the data manipulation and decision making. A processor comprises of:
A data path which contains the hardware necessary to perform all the operations. A controller tells the data path what needs to be done.
The registers act as intermediate storage for the data.

5. What does MAR stand for?
a) Main Address Register
b) Memory Access Register
c) Main Accessible Register
d) Memory Address Register

Explanation: MAR is a type of register which is responsible for the fetch operation. MAR is connected to the address bus and it specifies the address for the read and write operations.

6. If the control signals are generated by combinational logic, then they are generated by a type of _______________ controlled unit.
a) Micro programmed
b) Software
c) Logic
d) Hardwired

Explanation: The main task of a control unit is to generate control signals. There are two main types of control units:
A hardwired control unit generates control signals by using combinational logic circuits and the Micro programmed control unit generates control signals by using some softwares.

7. Which is the simplest method of implementing hardwired control unit?
a) State Table Method
b) Delay Element Method
c) Sequence Counter Method
d) Using Circuits

Explanation: There are 3 ways of implementing hardwired control unit:
A state table is the simplest method in which a number of circuits are designed based on the cells in the table.
A delay element method consists of a flowchart drawn for the circuit. A D-flip flop is used as a delay element.
A sequence counter method used k-modulo counter as a replacement for k delay elements.

8. A set of microinstructions for a single machine instruction is called ___________
a) Program
b) Command
c) Micro program
d) Micro command

Explanation: For every micro-operation, a set of microinstructions are written which indicate the control signals to be activated. A set of microinstructions is a micro program. The address of the next microinstruction is given by a Micro-program counter.

9. Micro-program consists of a set of microinstructions which are strings of 0s and 1s.
a) True
b) False