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IT Jobs Computer Science MCQs with Answers

179 practice MCQs on Computer Science for IT Jobs tests. Think of your answer first, then open "Show answer and explanation". These are practice questions, not official examination papers.

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Q111. What does ACID in databases stand for?

  1. Atomicity, Consistency, Isolation, Durability
  2. Atomicity, Concurrency, Isolation, Data
  3. Accuracy, Consistency, Integrity, Durability
  4. Access, Control, Integrity, Data
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Correct answer: A. Atomicity, Consistency, Isolation, Durability

ACID guarantees reliable transactions.

Q112. Which of the following is an output device?

  1. Mouse
  2. Monitor
  3. Scanner
  4. Keyboard
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Correct answer: B. Monitor

A monitor displays output.

Q113. What does HTML stand for?

  1. HyperText Making Language
  2. HyperTransfer Markup Language
  3. HyperText Markup Language
  4. HighText Markup Language
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Correct answer: C. HyperText Markup Language

HTML structures web pages.

Q114. Which device is both input and output?

  1. Mouse
  2. Touchscreen
  3. Speaker
  4. Printer
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Correct answer: B. Touchscreen

A touchscreen takes input and displays output.

Q115. What is cloud computing?

  1. A type of antivirus
  2. Using remote servers over the Internet to store and process data
  3. A weather prediction tool
  4. A programming language
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Correct answer: B. Using remote servers over the Internet to store and process data

Cloud computing delivers services over the Internet.

Q116. Which is the largest type of computer in size?

  1. Laptop
  2. Tablet
  3. Microcomputer
  4. Supercomputer
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Correct answer: D. Supercomputer

Supercomputers can fill rooms.

Q117. Which constraint ensures a column cannot have NULL values?

  1. CHECK
  2. NOT NULL
  3. UNIQUE
  4. DEFAULT
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Correct answer: B. NOT NULL

NOT NULL prevents empty values.

Q118. What are the four pillars of OOP?

  1. Class, Object, Method, Variable
  2. Encapsulation, Abstraction, Inheritance, Polymorphism
  3. Input, Output, Storage, Processing
  4. Compilation, Linking, Loading, Running
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Correct answer: B. Encapsulation, Abstraction, Inheritance, Polymorphism

These are the four fundamental OOP concepts.

Q119. Which tool is used to find and fix errors in a program?

  1. Browser
  2. Editor
  3. Compiler only
  4. Debugger
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Correct answer: D. Debugger

A debugger helps trace bugs.

Q120. What does MAN stand for?

  1. Main Area Network
  2. Multi Access Network
  3. Mobile Area Network
  4. Metropolitan Area Network
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Correct answer: D. Metropolitan Area Network

A MAN covers a city.

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