Computer GK

Computer GK - Part1

1) What is the first successful commercial microcomputer?
Altair 8800

2) When and who designed Altair 8800?
Micro Instrumentation Telemetry Systems (MITS) in 1974

3) Based on what technology Altair 8800 is built?
Intel 8080 CPU

4) The first electronic programmable (general purpose) computer built in United States is
ENIAC (Electronic numerical integrator and computer)

5) The following are the details of ENIAC
ENIAC has 18000 vacuum tubes, 1500 relays. Add or subtract 5000 times a second. Memory is 20 words. It used 200 Kilowatt power. It weighed 30 tons

6) What is the first electronic digital programmable computer?
Colossus

7) The following are the details of Colossus
It is built by Tommy flowers. It used paper-tape for input. It has large number of valves (vacuum tubes)

8) Who proposed the concept of modern computer?
Alan Turing in 1936. He called it Universal Turing machine

9) What is Open Systems Interconnection (OSI) model?
It is a model for network communications. It describes the 7 layers that computer systems use to communicate

10) What is the 7 layers of OSI model ?
Application, Presentation, Session, Transport, Network, Data link, Physical

11) What is the function of OSI model Application layer?
It identifies resource availability, communication partners. It synchronizes communication. Human-computer interaction layer

12) What is Multitasking?
It is the simultaneous execution of multiple tasks or processes

13) What is the function of OSI model Presentation layer?
It formats data in usable format for application layer. It also encrypts data

14) What is the function of OSI model Session layer?
It maintains connections and controls communication between computers

15) What is the function of OSI model Transport layer?
It transports data between systems and hosts

16) What is the function of OSI model Network layer?
It receives data from data link layer and deliver them to intended destinations

17) What is the function of OSI model Data link layer?
It transfers data between nodes. Also corrects the errors that occur in Physical layer

18) What is the function of OSI model Physical layer?
It transmits raw data bits across the network. For example voltages, radio frequencies etc.

19) What is TCP/IP(Transmission control Protocol/Internet Protocol) model?
It is a hierarchical protocol made of interactive models. It is based on standard protocols

20) What are the layers of TCP/IP model?
Application, Transport, Internet, Data link, Physical network

21) What is optical character recognition?
It is the conversion of printed or handwritten text to machine-encoded text

22) The following are computer generations and the related hardware

1st generation – vacuum tube,  2nd generation –  transistor,  3rd generation –  Integrated circuit(IC), 4th generation – Microprocessor and VLSI, 5th generation – Artificial intelligence

23) What is optical character recognition?
It is the conversion of printed or handwritten text to machine-encoded text

24) The following are computer generations and the related technologies examples

1st generation – ENIAC, IBM 701, 2nd generation – IBM 7094, 3rd generation – IBM 370, 4th generation – IBM PC and Apple Macintosh, 5th generation – Laptops, smart phones and tablets

25) What is Hardware?
Hardware is the physical components of a computer. Keyboard, monitor, mouse etc.

26) What is Software?
Software consists of programs and procedures that are needed for computer operation

27) What is a program?
A program is a set of instructions that are executed by a computer to perform a task

28) What is CPU (Central Processing Unit)?
CPU executes the instructions of the computer program

29) What parts does CPU have?
CPU has Arithmetic Logic Unit (ALU), Memory Unit and Control Unit.

30) How are computers classified?
Computers are classified by their computing power and their speed

31) What parts does computer have?
Computer has Input unit, CPU and output unit

32) What are input and output units?
Input unit is one data is entered into computer and output unit is one information comes out of computer

33) What are the types of computers?

Personal computer(PC) is for Individual use, Workstation is high performance computer for single use and typically linked in Local Area Network(LAN),  Minicomputer is for multiprocessing and multi-user, Mainframe is a very large computer supporting thousands of users simultaneously and Supercomputer is very fast computer used for special applications like weather forecasting and scientific calculations

34) What is Compiling?
Compiling is converting a program into machine code or low-level program. It creates an executable program

35) What is a browser?
Browser is a software that is used to browse the Internet

36) What is a driver?
It is a software through which operating system and the hardware communicate

37) What is Operating System?
It is the software that helps computer basic functions like controlling peripherals

38) What is Computer memory?
Computer memory is space where data and programs that are required to be processed are stored.

39) What is RAM(Random access memory)?
It is Central Processing Unit’s (CPU) internal memory to store data, programs and results. It is read or write volatile(temporary) memory. It is erased once the machine is switched off

40) What are the 2 types of RAM (Random access memory)?
a) Static RAM. It retains contents when power is on. It is used as cache memory and is very fast
b) Dynamic RAM. It needs to be refreshed continuously. Mostly used because it is cheap.

41) What is ROM(Read Only memory)?
It can be read but cannot be written to. It is non-volatile (stored permanently). It has instructions required to start the computer

42) What are the advantages of ROM?
Permanent, Cheap, Reliable, static, cannot be accidentally changed and easy to test
43) What are the various types of ROM (Read only Memory)?

PROM (Programmable ROM) is programmed only once by user and is not erasable. EPROM (Erasable and programmable ROM) Can be erased by exposing to UV light for 40 minutes, EEPROM (Electrically Erasable and programmable ROM) Can be erased and reprogrammed 10,000 times. Can be erased 1 byte at a time, MROM (Masked ROM) Contains pre-programmed instructions

44) Some input devices of computer

Computer input deviceDetails
Bar Code ReaderUsed for reading bar codes
Magnetic Ink Card Reader (MICR)This is identifies the numeric data printed with magnetically charged ink. The reading process is known as “Magnetic Ink Character Recognition”
Digitizer
Converts analog information to digital
Joystick
Pointing device used to move cursor
Light pen
Pointing device to select or to draw
Track ball
Pointing device used to move cursor using ball

45) What are some output devices of computer?
Monitor and Printer

46) What is a monitor/Visual Display Unit(VDU)?
It is the main output device of a computer.

47) What are the types of monitors?
Cathode-Ray tube (CRT), Light-Emitting Diodes(LED) and Liquid-Crystal Device(LCD). LED and LCD are flat-panel displays. Flat panel displays require less power and weigh less

48) What is a Cathode-Ray tube (CRT)?
It is a vacuum tube containing electron guns whose beams are converted to display images on screen

49) What is an LED(Light-Emitting Diode) monitor?
It is an emissive flat-display monitor. It converts electrical energy into light. Example is Plasma

50) What is an LCD(Liquid-Crystal Device) monitor?
It is a non-emissive flat-display monitor. It converts light to graphics patterns using optical effects

51) What are the 2 types of printers?
Impact printers and non-impact printers

52) What are impact printers?
Impact printers print the characters by striking them on the ribbon. They are noisy and low cost

53) What are the types of impact printers?

54) What are character printers?
They print one character at a time

55) What are Dot Matrix printers?
Characters are printed in dot pattern. They are easy to print and are cheap. Can print other languages. They are slow and are print quality is poor

56) What are Daisy Wheel printers?
These are used for word-processing. They are reliable but slower and expensive than dot matrix printer. They are noisy. The print quality is good. Fonts can be changed

57) What are line printers?
They print one line at a time

58) What are drum printers?
It is like drum in shape. It has tracks equal to size of paper. 48, 64 and 96 character sets are available. A character set is on a track. One rotation prints one line. They are fast and can print up to 2000 lines per minute. They are expensive and fonts cannot be changed

59) What are chain printers?
In chain printer a chain of character sets are used. The print chain rotates and prints. Different languages can be used and fonts can be changed. They are noisy

60) What are non-impact printers?
They print without ribbon. They print a page at a time. They are also called page printers. They are faster, not noisy, high quality and can change fonts. 2 types are laser printers and inkjet printers

61) What are laser printers?
They use laser light to print. They are very fast and of high quality. Fonts can be changed. They are expensive and multiple copies cannot be printed at a time.

62) What are inkjet printers?
They print by spraying ink onto paper. They are of high quality. They make less noise and color printing can be done. They are reliable but expensive. They are slow compared to laser printers

63) What is open source software?
The source code is available for end-user and can be modified. No restrictions on use and redistribution.

64) What is cyber or computer security?
It is the protection of computer systems and data from attack

65) What is 90/10 rule of computer security?
This means 90% of security is from following good computer practices like having strong passwords, updated antivirus, not downloading or clicking on unknown files and 10% are technical

66) What is Malware?
Malware is malicious software irrespective of its distribution, work or intent. It has various goals

67) What are the types of malware?
Ransomware, Scareware, Worms, Spyware, Adware and fileless malware, Viruses, Trojan Horses and Bots

Type of Malware
Details
Ransomware
It demands users to pay ransom to regain access to their computer
Scareware
It pops up on user’s computer with loud alarms or otherwise saying that the computer has been infected. Asks the user to buy a fake antivirus
Worms
It is a standalone program. It replicates itself and spreads over a network. It exploits weak computer systems or spreads through email attachment. The first worm is Morris worm created by a graduate in 1988
Spyware
It collects information about user secretly. Keylogger is a spyware that records keystrokes
Adware
It sends unwanted advertisements to users
Fileless malware
It operates in memory. It does not download code
Virus
Virus need an already infected program to spread. They attach generally to executable or doc
Trojan Horses
It disguises as a legitimate file and need a host to spread
Bot(Zombie computer)
It is a malware infected computer remotely controlled by hacker

68) What is Phishing?
It is an attack used to steal user information like passwords, financial information etc

69) What is spoofing?
It is identity theft. A person or program pretending as another person or program

70) What is eavesdropping?
It is secretly listening to a conversation

71) What is tampering?
Intentionally and unauthorizedly modifying computer systems or its components