HR & Technical Interview Questions With Answers.

21. List Five Services Provided By An Operating System. Explain How Each Provides Convenience To The Users. Explain Also In Which Cases It Would Be Impossible For User-Level Programs To Provide These Services. PROGRAM EXECUTION: The operating system loads the contents (or sections) of a file into memory and begins its execution. A user-level program could not be trusted to properly allocate CPU time. I/O OPERATIONS: Disks, tapes, serial lines, and other devices must be communicated with at a very low level. The user need only specify the device and the operation to perform on it, while the system converts that request into device or controller specific commands. User-level programs cannot be trusted to only access devices they should have access to, and to only access them when they are otherwise unused. FILE-SYSTEM MANIPULATION: There are many details in file creation, deletion, allocation, and naming that users should not have to perform. Blocks of disk space are

16. Discuss Distributed Operating System? Answer: An operating system that manages a group of independent computers and makes them appear to be a single computer is known as a distributed operating system. The development of networked computers that could be linked and made to communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system. Amoeba, Plan9 and LOCUS (developed during the 1980s) are some examples of distributed operating systems. 17. Discuss Embedded Operating System? Answer: The operating systems designed for being used in embedded computer systems are known as embedded operating systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE, FreeBSD and Minix 3 ar

11. What Are The Three Major Activities Of An Operating System In Regard To File Management? Answer: Three major activities of an operating system in regards to file management are: Creating and deleting files. Creating and deleting directories. Supporting file and directory primitives. Mapping files onto secondary storage. File backup. 12. Discuss Various Types Of Operating Systems? Answer: Different types of operating systems available are: Real-time Operating System. Multi-user and Single-user Operating Systems. Multi-tasking and Single-tasking Operating Systems. Distributed Operating System. Embedded System. Mobile Operating System. Batch Processing and Interactive Operating Systems. 13. Discuss Real Time Operating Systems? Answer: Real-time operating systems are used to control machinery, scientific instruments and industrial systems. A very important part of an RTOS is managing the resources of the computer so that a particular operation executes in

6. What Is BIOS In Operating System? Answer: The Basic Input Output System, usually referred to as BIOS, is a software stored on a small memory chip on the motherboard. BIOS (Basic Input/Output System) is a program which a personal computer's microprocessor uses to get the computer system started after you turn it on. BIOS instructs the computer on how to perform a number of basic functions such as booting and keyboard control. BIOS is also used to identify and configure the hardware in a computer such as the hard drive, floppy drive, optical drive, CPU, memory, etc. 7. What Are The Advantages & Disadvantages Of Multiprocessor Systems? Answer: Advantages of Microprocessor Systems are: Increased throughput - With more processors, more work can be accomplished in less time. Economy of scale - Peripheral devices may be shared amongst multi-processor systems. Increased reliability - If one processor crashes, then the others may continue to operate. Disadvant

1. What Is An Operating System? An operating system is the most important software that runs on a computer. An operating system is a program that acts as an intermediary between the user and the computer hardware. It manages the computer's memory, processes, and all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's "language". Without an operating system, a computer is useless. The purpose of an OS is to provide a convenient environment in which user can execute programs in a convenient and efficient manner. 2. What Are The Basic Functions Of Operating Systems? Functions of an operating system are: Shield the user from the intricate low-level details and provide an easier to program and more powerful interface to the machine or network => virtual machine. Manage the system resources: Protection, Scheduling, Sharing, File system, Accounting, etc. This function is obviously