UNIT -1 : COMPUTER SYSTEM

TOPIC:  DATA REPRESENTATION IN DIGITAL COMPUTER 

Q: What is computer system 

A computer system is a combination of hardware, software, data, and human resources that work together to perform computing tasks.

Computer systems can vary in size and complexity, ranging from small embedded systems found in appliances and gadgets to large-scale mainframe computers and supercomputers used for scientific research and complex calculations. The basic function of any computer system is to input data, process it according to instructions provided by software, store the results, and output the processed data.

Q: What is data representation in digital computer 

Data representation in a digital computer refers to the method by which information such as numbers, text, images, and multimedia is encoded and stored in binary form (0s and 1s) for processing and manipulation by the computer's hardware and software.

let's take the example of representing the number 5 in a digital computer.

In the digital world, everything is represented using binary digits (bits), which can be either 0 or 1.

The decimal number 5 can be represented in binary as 101. Here's how it works:

• In the binary system, each digit position represents a power of 2.
• Starting from the rightmost digit, the positions are 2^0, 2^1, 2^2, and so on.
• So, in the binary number 101, we have:
  • 1 * 2^2 (which is 4)
  • 0 * 2^1 (which is 0)
  • 1 * 2^0 (which is 1)
• Adding these together (4 + 0 + 1), we get 5.

So, in binary, 101 represents the decimal number 5. This is how data, including numbers, is represented in digital computers.

Multiple Choice Questions

1. In a binary number system, how many unique symbols are used to represent values? a) 2 b) 8 c) 10 d) 16

2. What is the binary representation of the decimal number 10? a) 1010 b) 1000 c) 1101 d) 0101

3. What is the hexadecimal representation of the binary number 101011? a) AB b) 2B c) 5B d) 6B

4. How many bits are in a byte? a) 4 b) 8 c) 16 d) 32

5. Which data representation format is commonly used to represent characters in computers? a) ASCII b) Unicode c) EBCDIC d) Binary Coded Decimal (BCD)

6. How many bits are required to represent 256 unique values? a) 8 b) 16 c) 32 d) 64

7. What is the octal representation of the binary number 110110? a) 166 b) 324 c) 56 d) 326

8. Which of the following is a signed integer representation method? a) Two's complement b) Excess-3 code c) Gray code d) ASCII code

9. Which of the following data storage units is the smallest? a) Kilobyte (KB) b) Megabyte (MB) c) Gigabyte (GB) d) Bit

10. What is the IEEE 754 standard used for? a) Representing floating-point numbers b) Encoding text characters c) Defining network protocols d) Specifying computer graphics formats

Answers:

1. a) 2
2. a) 1010
3. c) 5B
4. b) 8
5. a) ASCII
6. a) 8
7. a) 166
8. a) Two's complement
9. d) Bit
10. a) Representing floating-point numbers

TOPIC: ANALOGUE AND DIGITAL SIGNAL

Q: What is analogue and digital signal

            An analogue signal is a continuous representation of a physical phenomenon, where the signal's amplitude varies smoothly over time. Examples include voltage fluctuations in electrical circuits, sound waves in air, and light intensity in optical fibers.

On the other hand, a digital signal is a discrete representation of information where the signal is represented using discrete values or symbols, typically binary digits (0s and 1s). Digital signals are generated by sampling and quantizing analog signals into discrete levels. These discrete levels are used to represent different states or values of the signal. Digital signals are widely used in digital communication systems, computers, and electronic devices due to their robustness against noise and distortion and ease of processing and transmission.

In summary, analog signals are continuous and represent information through varying physical quantities, while digital signals are discrete and represent information through discrete symbols or values.

Q: Difference between analog and digital signals

The main differences between analogue and digital signals lie in their representation, properties, and usage:

1. Representation:

   • Analog Signal: An analog signal is a continuous representation of a physical phenomenon, where the signal's amplitude varies smoothly over time. It can take any value within a range, and its amplitude is directly proportional to the quantity being measured. Examples include voltage fluctuations in electrical circuits, sound waves, and light intensity.
   • Digital Signal: A digital signal is a discrete representation of information, where the signal is represented using discrete values or symbols, typically binary digits (0s and 1s). It consists of a sequence of discrete levels, and each level represents a specific state or value of the signal.

2. Properties:

   • Analog Signal: Analog signals are susceptible to noise, distortion, and degradation over long distances. They can have an infinite number of possible values within their range, and their properties vary continuously over time.
   • Digital Signal: Digital signals are less susceptible to noise and distortion compared to analog signals. They have discrete levels, which makes them easier to process, transmit, and store. Digital signals can be transmitted over long distances without significant degradation, as they can be regenerated and cleaned up.

3. Usage:

• Analog Signal: Analog signals are commonly used in audio systems, video systems, telecommunication systems, and various sensors where the quantity being measured is continuous in nature. They are often used in applications where real-world data needs to be represented accurately and continuously.
• Digital Signal: Digital signals are widely used in digital communication systems, computers, and electronic devices. They are ideal for storing and processing information digitally, such as text, images, videos, and numerical data. Digital signals are also used in modern telecommunication networks, including the internet, mobile phones, and digital television.
4. Multiple Choice Questions
5. Here are some multiple-choice questions (MCQs) related to analog and digital computers: 1. Which type of computer processes continuous data and represents information using physical quantities? a) Analog Computer b) Digital Computer c) Hybrid Computer d) Mainframe Computer 2. What is the primary advantage of digital computers over analog computers? a) Higher processing speed b) Greater accuracy and precision c) Lower cost d) Simplicity of design 3. Which type of computer is best suited for solving mathematical equations and simulating physical systems? a) Analog Computer b) Digital Computer c) Hybrid Computer d) Supercomputer 4. Which of the following is an example of an analog input device? a) Keyboard b) Mouse c) Microphone d) Printer 5. What type of signal does an analog computer process? a) Continuous b) Discrete c) Binary d) Decimal 6. Which type of computer is commonly used in control systems and scientific instruments? a) Analog Computer b) Digital Computer c) Hybrid Computer d) Personal Computer 7. What is the fundamental unit of information in a digital computer? a) Bit b) Byte c) Kilobyte d) Megabyte 8. Which type of computer is typically used for processing audio and video signals? a) Analog Computer b) Digital Computer c) Hybrid Computer d) Supercomputer 9. What is the primary disadvantage of analog computers compared to digital computers? a) Limited processing speed b) Higher cost c) Greater susceptibility to noise and distortion d) Incompatibility with modern software 10. Which type of computer uses both analog and digital components for processing data? a) Analog Computer b) Digital Computer c) Hybrid Computer d) Mainframe Computer Answers: 1. a) Analog Computer 2. b) Greater accuracy and precision 3. b) Digital Computer 4. c) Microphone 5. a) Continuous 6. a) Analog Computer 7. a) Bit 8. b) Digital Computer 9. c) Greater susceptibility to noise and distortion 10. c) Hybrid Computer