Operating Systems Interview Questions You'll Most Likely Be Asked

By Vibrant Publishers

• 225 Operating Systems Interview Questions
• 77 HR Interview Questions 
• Real life scenario-based questions
• Strategies to respond to interview questions
• 2 Aptitude Tests

Operating Systems In

• Language: English
• Publisher: Vibrant Publishers
• Release date: May 10, 2018
• ISBN: 9781946383204

Book preview

Operating Systems

Interview Questions

You'll Most Likely Be Asked

Job Interview Questions Series

www.vibrantpublishers.com

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Operating Systems Interview Questions You'll Most Likely Be Asked

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Table of Contents

1. General

2. Operating System Design

3. Inter-Process Communication

4. Threads

5. CPU Scheduling

6. Scheduling Algorithms

7. Process Synchronization

8. Memory Management

9. Windows 10

10. Linux

11. Mac OS

HR Interview Questions

INDEX

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Operating Systems

Interview Questions

Review these typical interview questions and think about how you would answer them. Read the answers listed; you will find best possible answers along with strategies and suggestions.

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General

1: What is Operating System?

Answer:

An Operating System is a software between computer hardware and the user of the computer. The primary objective of an operating system is to offer an environment to enable end user execute programs conveniently and proficiently. An operating system is also responsible for managing computer hardware.

2: What are the components of a computer system?

Answer:

There are four components of computer system. They are:

a) Computer Hardware – It provides computing resources to a computer system and is composed of several units including Central Processing Unit (CPU), Memory and Input / Output devices

b) Application programs – These are the programs which specify the methods to solve user’s problems. Example of application programs are word processor, compiler, spreadsheet etc.

c) Operating System – It is a software which controls the usage of computer hardware among different application programs of different users

d) User – A user is the person who is using the computer system

3: What is bootstrap program?

Answer:

A bootstrap program is an initial program which is started when a computer is powered on or rebooted. The objective of a bootstrap program is to initialize the CPU registers, device controllers, memory contents etc. and to load and start executing the operating system. Bootstrap program is typically stored in read-only- memory (ROM) of a computer system.

4: What is an interrupt?

Answer:

An interrupt may be defined as an occurrence of an event which causes the Central Processing Unit to suspend executing current program, transfer the control to another program called service routine and upon completion of service routine, resume executing the suspended program. An interrupt may be caused by either hardware or software.

5: What is interrupt vector?

Answer:

An interrupt vector is an array of memory locations which point to interrupt service routine for various devices. It is stored in the form of table of pointers at starting location of memory for example, first 100 memory locations. An interrupt vector is usually indexed by unique device number along with interrupt request in order to locate the address of interrupt service routine for an interrupting device.

6: Explain a typical instruction execution cycle.

Answer:

An instruction execution cycle consists of following steps:

a) Fetching instruction from main memory and store it in instruction registers

b) Decoding the instruction and fetch the required operands from main memory

c) Executing the instruction

d) Store the result in main memory

7: Why is it not possible to store all instructions and data in main memory?

Answer:

It is not possible to store all instructions and data in main memory because:

a) The size of main memory is small compared to amount of instructions and data that can be stored permanently

b) Main memory is volatile because it loses its content when power is switched off

8: What is secondary storage?

Answer:

Secondary storage is a storage that can hold large amount of instruction and data permanently. For example: magnetic disc, magnetic tape etc. Usually, majority of the programs such as spreadsheet, browser, compiler etc. are stored on magnetic disc and are loaded in main memory when required.

9: Explain Direct Memory Access (DMA).

Answer:

Direct Memory Access is a method to transfer a complete block of data between device controller’s buffer storage and main memory without intervention of CPU (Central Processing Unit). The advantage of Direct Memory Access is that there is only one interrupt generated per block of data to inform the device driver that operation has been completed. Direct Memory Access is typically used in situations where bulk transfer of data is required such as disk input /output.

10: Describe single processor computer system.

Answer:

A single process computer system has only one general purpose microprocessor which can execute a general-purpose instruction set as well as instructions from user processes and it may contain one or more special purpose microprocessors. Therefore, if a computer system contains a special-purpose microprocessor such as Input/output microprocessor in addition to a general-purpose microprocessor then the computer system is still considered as a single processor computer system.

11: Describe multiprocessor computer system.

Answer:

A multiprocessor computer system contains two or more general purpose microprocessors which can communicate with other and share a computer bus, memory and Input/output devices. A multiprocessor computer system may contain one or more special purpose microprocessors.

12: What are advantages of multiprocessor computer system?

Answer:

The advantages of multiprocessor computer system are:

a) Increased efficiency – The major advantage of multiprocessor computer system is that efficiency of the system increases because two or more processors are involved in executing the task and therefore task gets completed in less amount of time

b) Reduced cost – When several programs are required to operate on same set of data then a multiprocessor system costs less than an equivalent multiple single processor computer system since a multiprocessor computer system share peripherals and storage devices

c) Increased reliability – If a task is distributed equally among the microprocessors then failure of one microprocessor does not cause a multiprocessor system to halt

13: What is fault tolerant system?

Answer:

A fault tolerant computer system can continue its operation despite failure of a component. A fault tolerant computer system requires the ability to detect, diagnose and possibly correct the fault. An example of fault tolerant computer system is HP Non-Stop system which both hardware and software are duplicated to make sure operation is continued.

14: What are the types of multiprocessor computer systems?

Answer:

There are two types of multiprocessor computer systems:

a) Asymmetric multiprocessor computer system – In this multiprocessor computer system, each processor is assigned a specific task

b) Symmetric multiprocessor computer system – In this multiprocessor computer system, each processor can perform all tasks within operating system

15: Explain Asymmetric multiprocessor computer system.

Answer:

In this multiprocessor computer system, each processor is assigned a specific task. A master processor allocates the work to other processors and controls the complete system. Therefore, there is a master-slave relationship exists among the processors. Example of the operating system which uses asymmetric multiprocessing is Sun Microsystems’s SunOS.

16: Explain Symmetric multiprocessor computer system.

Answer:

In this multiprocessor computer system, each processor can execute all tasks within operating system. All the processors are considered as peers