22516 Operating System External Oral / Viva Practice Questions with Answers
1) What is an operating system?
The operating system is a software program that facilitates computer hardware to communicate and operate with the computer software. It is the most important part of a computer system without it computer is just like a box.
2) What is the main purpose of an operating system?
There are two main purposes of an operating system:
- It
is designed to make sure that a computer system performs well by managing
its computational activities.
- It provides an environment for the development and execution of programs.
3) What are the different operating systems?
- Batched
operating systems
- Distributed
operating systems
- Timesharing
operating systems
- Multi-programmed
operating systems
- Real-time operating systems
4) What is a socket?
A socket is used to make connection between two applications. Endpoints
of the connection are called socket.
5) What is a real-time system?
Real-time system is used in the case when rigid-time requirements have
been placed on the operation of a processor. It contains a well defined and
fixed time constraints.
6) What is kernel?
Kernel is the core and most important part of a computer operating
system which provides basic services for all parts of the OS.
7) What is monolithic kernel?
A monolithic kernel is a kernel which includes all operating system code
is in single executable image.
8) What do you mean by a process?
An executing program is known as process. There are two types of
processes:
- Operating
System Processes
- User Processes
9) What are the different states of a process?
A list of different states of process:
- New
Process
- Running
Process
- Waiting
Process
- Ready
Process
- Terminated
Process
10) What is the difference between micro kernel and macro kernel?
Micro kernel: micro kernel is the kernel which runs minimal performance
affecting services for operating system. In micro kernel operating system all
other operations are performed by processor.
Macro Kernel: Macro Kernel is a combination of micro and monolithic kernel.
12) What is the difference between process and program?
A program while running or executing is known as a process.
13) What is the use of paging in operating system?
Paging is used to solve the external fragmentation problem in operating
system. This technique ensures that the data you need is available as quickly
as possible.
14) What is the concept of demand paging?
Demand paging specifies that if an area of memory is not currently being
used, it is swapped to disk to make room for an application's need.
15) What is the advantage of a multiprocessor system?
As many as processors are increased, you will get the considerable
increment in throughput. It is cost effective also because they can share
resources. So, the overall reliability increases.
16) What is virtual memory?
Virtual memory is a very useful memory management technique which
enables processes to execute outside of memory. This technique is especially
used when an executing program cannot fit in the physical memory.
17) What is thrashing?
Thrashing is a phenomenon in virtual memory scheme when the processor
spends most of its time in swapping pages, rather than executing instructions.
18) What are the four necessary and sufficient conditions behind the
deadlock?
These are the 4 conditions:
1) Mutual Exclusion Condition: It specifies that the
resources involved are non-sharable.
2) Hold and Wait Condition: It specifies that there must be
a process that is holding a resource already allocated to it while waiting for
additional resource that are currently being held by other processes.
3) No-Preemptive Condition: Resources cannot be taken away
while they are being used by processes.
4) Circular Wait Condition: It is an explanation of the
second condition. It specifies that the processes in the system form a circular
list or a chain where each process in the chain is waiting for a resource held
by next process in the chain.
19) What is a thread?
A thread is a basic unit of CPU utilization. It consists of a thread ID, program counter, register set and a stack.
20) What is FCFS?
FCFS stands for First Come, First Served. It is a type of scheduling
algorithm. In this scheme, if a process requests the CPU first, it is allocated
to the CPU first. Its implementation is managed by a FIFO queue.
21) What is SMP?
SMP stands for Symmetric MultiProcessing. It is the most common type of
multiple processor system. In SMP, each processor runs an identical copy of the
operating system, and these copies communicate with one another when required.
22) What is RAID? What are the different RAID levels?
RAID stands for Redundant Array of Independent Disks. It is used to
store the same data redundantly to improve the overall performance.
Following are the different RAID levels:
RAID 0 - Stripped Disk Array without fault tolerance
RAID 1 - Mirroring and duplexing
RAID 2 - Memory-style error-correcting codes
RAID 3 - Bit-interleaved Parity
RAID 4 - Block-interleaved Parity
RAID 5 - Block-interleaved distributed Parity
RAID 6 - P+Q Redundancy
23) What is deadlock? Explain.
Deadlock is a specific situation or condition where two processes are
waiting for each other to complete so that they can start. But this situation
causes hang for both of them.
24) Which are the necessary conditions to achieve a deadlock?
There are 4 necessary conditions to achieve a deadlock:
- Mutual
Exclusion: At
least one resource must be held in a non-sharable mode. If any other
process requests this resource, then that process must wait for the
resource to be released.
- Hold
and Wait: A
process must be simultaneously holding at least one resource and waiting
for at least one resource that is currently being held by some other
process.
- No
preemption: Once
a process is holding a resource ( i.e. once its request has been granted
), then that resource cannot be taken away from that process until the
process voluntarily releases it.
- Circular Wait: A set of processes { P0, P1, P2, . . ., PN } must exist such that every P[ i ] is waiting for P[ ( i + 1 ) % ( N + 1 ) ].
25) What is Banker's algorithm?
Banker's algorithm is used to avoid deadlock. It is the one of
deadlock-avoidance method. It is named as Banker's algorithm on the banking
system where bank never allocates available cash in such a manner that it can
no longer satisfy the requirements of all of its customers.
26) What is the difference between logical address space and physical
address space?
Logical address space specifies the address that is generated by CPU. On
the other hand physical address space specifies the address that is seen by the
memory unit.
27) What is fragmentation?
Fragmentation is a phenomenon of memory wastage. It reduces the capacity
and performance because space is used inefficiently.
28) How many types of fragmentation occur in Operating System?
There are two types of fragmentation:
- Internal
fragmentation: It
is occurred when we deal with the systems that have fixed size allocation
units.
- External
fragmentation: It
is occurred when we deal with systems that have variable-size allocation
units.
29) What is spooling?
Spooling is a process in which data is temporarily gathered to be used
and executed by a device, program or the system. It is associated with
printing. When different applications send output to the printer at the same
time, spooling keeps these all jobs into a disk file and queues them
accordingly to the printer.
30) What is the difference between internal commands and external
commands?
Internal commands are the built-in part of the operating system while external commands are the separate file programs that are stored in a separate folder or directory.
31) What is semaphore?
Semaphore is a protected variable or abstract data type that is used to
lock the resource being used. The value of the semaphore indicates the status
of a common resource.
There are two types of semaphore:
- Binary
semaphores
- Counting semaphores
32) What is a binary Semaphore?
Binary semaphore takes only 0 and 1 as value and used to implement
mutual exclusion and synchronize concurrent processes.
36) What are the advantages of multithreaded programming?
A list of advantages of multithreaded programming:
- Enhance
the responsiveness to the users.
- Resource
sharing within the process.
- Economical
- Completely
utilize the multiprocessing architecture.
37) What is the difference between logical and physical address space?
Logical address specifies the address which is generated by the CPU
whereas physical address specifies to the address which is seen by the memory
unit.
Disclaimer:
Thankyou Javatpoint for
preparing this Questions, All Credit goes to
Javatpoint. We have used their content for helping students in their
VIVA / Oral / External Exam so they can score Great Marks in it.