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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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Q121. Which is the brain of the computer?

  1. Keyboard
  2. Mouse
  3. Monitor
  4. CPU
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Correct answer: D. CPU

The CPU processes instructions.

Q122. Which SQL command modifies existing rows?

  1. UPDATE
  2. SELECT
  3. CREATE
  4. DROP
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Correct answer: A. UPDATE

UPDATE changes data.

Q123. Which keyword is used to define a function in Python?

  1. define
  2. def
  3. function
  4. func
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Correct answer: B. def

def begins a function definition.

Q124. What is phishing?

  1. A programming technique
  2. A search algorithm
  3. Fraudulent attempt to steal sensitive information
  4. A type of fishing software
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Correct answer: C. Fraudulent attempt to steal sensitive information

Phishing tricks users into revealing credentials.

Q125. Who developed Java?

  1. Guido van Rossum
  2. Dennis Ritchie
  3. Bjarne Stroustrup
  4. James Gosling
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Correct answer: D. James Gosling

Gosling created Java at Sun Microsystems.

Q126. What is a pointer in C?

  1. A loop
  2. A function
  3. A comment
  4. A variable that stores a memory address
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Correct answer: D. A variable that stores a memory address

Pointers hold addresses.

Q127. What is a computer virus?

  1. A search engine
  2. A web browser
  3. A hardware part
  4. A program that spreads by attaching to other files
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Correct answer: D. A program that spreads by attaching to other files

Viruses replicate and spread.

Q128. Which of the following is a NoSQL database?

  1. MongoDB
  2. Oracle
  3. PostgreSQL
  4. MySQL
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Correct answer: A. MongoDB

MongoDB is a document NoSQL database.

Q129. What is the output of 5 + 3 * 2 in most programming languages?

  1. 13
  2. 10
  3. 16
  4. 11
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Correct answer: D. 11

Multiplication has higher precedence.

Q130. Which device connects multiple networks and forwards packets?

  1. Hub
  2. Router
  3. Switch
  4. Repeater
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Correct answer: B. Router

A router connects networks.

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