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1. What is data? What is the output of data processing system?

Data are raw facts and figures. Data processing system transforms data into useful information.

2. State the basic units of the computer. Name the subunits that make up the CPU, and give the function of each of the units.

The basic units of a computer are:

1. Input unit      2. Central Processing Unit (CPU)    3. Output Unit     4. Memory


  • The CPU has two subunits: the control unit (CU) and the arithmetic logic unit (ALU).

                   ♦ The Control unit controls the entire operation being carried out.

                   ♦ The ALU performs the arithmetic and logical operations.

3. What is the function of memory? What are its measuring units?

The memory temporarily holds the data the information during processing. The smallest unit of memory is a byte (8bits), A byte can store one character in binary forms. Other measuring units are 1 kilobyte (KB) equal to 1024 (210) bytes, 1 megabyte (MB) equal to 1024 KB, 1 Gigabyte (GB) equal to 1024 MB and 1 Terabyte (TB) equal to 1024 GB.

4. What are the difference between hardware, software, and firmware?

Hardware are the physical tangible components of a computer system. Software are the computer programs that govern the operation of computers. Firmware are the prewritten programs permanently stored in read-only memory. These configure the computer and are not easily modifiable by the user.

5. Give examples for system software and application software.

Examples of System software are:

      i. Operating system        ii. Language Processor      iii. Application Software

Examples of application software are:

      i. Customized Software    ii. General software. 

6. What are the three types of computers? How do they differ?

The three types of computers are: (i) Digital   ii. Analog     iii. Hybrid

  • Digital computers deal with discrete quantities
  • Analog computers deal with physical quantities. They measure rather than counting as the digital computers do.
  • Hybrid computers combine the characteristics of analog and digital computers.

7. How is a compiler different from interpreter?

A compiler converts the source code (Program in HLL) into object code (Machine Language code) and reports all the errors along with their line numbers.

An interpreter converts source code into object code line and executes it there and then. It does not shift to the next line if the line is erroneous.

8. What are the different types of digital computers based on their performance?

Performance wise digital computers are of following four types.

1. Microcomputers 

2. Mini computers   

3. Mainframe computers     

4. Super computers.

9. Name the super computers developed in India.


10. What are the major strengths and weaknesses of computer?


1. Speed   2. Accuracy   3. Reliability   4. High Storage Capacity   5. Versatility


1. Lack of decision making power 2. Zero IQ.

11. Why is binary language often termed as machine language? Why is machine language required?

A computer (the machine) operates on electricity. Thus, it can understand only electricity signals just two unique signals that are just two- ON and OFF or high voltage and low voltage. Thus it needs a language that uses just two unique symbols to represent these two states of electricity. Therefore, a computer works on the machine language. The binary language is often termed as machine language as it fulfills the condition of using two unique symbols to represent two states of electricity.

12. Who invented the punched card?

The concept of punched cards was devised by Charles Babbage but it was actually fabricated by Herman Hollerith.

13. What is MICR? Where is it mostly used? What is the major (dis) advantage of MICR as a general purpose input medium?

MICR stands for Magnetic Ink Character Reader. This device can read human readable characters that are printed using a special magnetic ink. The MICRs are mostly used in banks. The major advantages of MICR is accuracy and its speed. The major disadvantages of MICR is that the numbers of characters that can be recorded with present techniques is very limited. Also, the characters cannot be read repeatedly without losing their magnetism.

14. What is the different between OCR and OMR?

An Optical Character Reader (OCR) is used to read characters of special type font that are printed on conventional paper with conventional ink.

On the other hand, an optical mark reader (OMR) is used to transcribe marks that are marked with a dark pencil or ink on a special preprinted form (example answer sheet of a multiple choice question paper where a choice of answer can be reflected by shading the appropriate box).

An OCR also comprises of a logical system that attempts to determine which of the possible characters is being examined.

15. What are the advantages and disadvantages of OCR?

The main advantage of an OCR is the accuracy of the documents can be ensured. The disadvantages of an OCR are : (i) limited number of characters offered by it, and (ii) their high cost.

16. What are the two categories and disadvantages of OCR?

The printers can be classified into following two categories:

Impact Printers. In these type of printers, there is a physical contact between the paper and the printer head.

These can further be classified as:  (i) Line printer which can print a line at a time, (ii) Character printers which can print a character at a time.

Non-Impact Printers. In these type of printers, there is not physical contact between the paper and the printer head. The printing takes place with some electromagnetic or thermal or laser techniques. The non-impact printers are more speedy than impact printers.

17. Explain working of a dot-matrix printer.

In the dot-matrix printer (dmp), an arrangement of tiny hammers strikes to produce the desired characters. Each hammer prints a small dot on the paper.

The printing head of dmp's contains a vertical array of pins. As the head moves across the paper, selected pins "fire" against an inked ribbon to form a pattern of dots on the paper. Using this features, a dmp can even drew pictures, graphs etc. In the figure, the capital letters are formed by 5-dot rows and 7-dot columns (that is a row having 5 dots and a column having 7 dots). Such a patterns is called a 5 x 7 matrix. But, the printing head of a dmp consists of 9 pins where bottom 2 pins where bottom 2 pins are used for descenders (lower portions) of small letters like y, i etc.

18. What is the difference between RAM and ROM?

RAM refers to random access memory where both read and write operations can take place. But the RAM is a volatile memory; its contents are lost when power is turned off.

ROM refers to read only memory where only read operation can take place. The ROM is a non - volatile memory.

Both RAM and ROM are parts of the primary memory.

19. What does a bus mean?

A bus is a group of conducting lines that carriers data, address,and control signals between CPU and memory.

20. Why is data bus bi- directional?

Data bus is bi-directional because same bus is used for data transmission from microprocessor to memory location or input/output device . This is there reason data bus is bi-directional.

21. What is a port? Name some port types.

Ports are the points on computer having associated circuitry to allow connection of external devices with computer. Ports can be or various types.

  • Serial ports
  • Parallel ports
  • USB ports
  • AGP ports
  • InfraRed port
  • BlueTooth ports
  • Network ports
  • Phone ports.

22. Can you pick the one that offers you maximum read speed along with maximum capacity.

Memory stick ProDuo, SD card, MMC plus, Smart media Card

Out of these, memory Stick ProDuo offers maximum read speed along with maximum capacity.

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