Operating System MCQ

 Q.1 The field that contains a segment index or an internal index is called

(A) target datum 

(B) target offset

(C) segment field 

(D) fix dat

Ans: (A)

Q.2 A program in execution is called

(A) process 

(B) function

(C) CPU 

(D) Memory

Ans: (A)

Q.3 Jobs which are admitted to the system for processing is called

(A) long-term scheduling 

(B) short-term scheduling

(C) medium-term scheduling 

(D) queuing

Ans: (A)

Q.4 A set of techniques that allow to execute a program which is not entirely in memory is called

(A) demand paging 

(B) virtual memory

(C) auxiliary memory 

(D) secondary memory

Ans: (B)

Q.5 SSTF stands for

(A) Shortest-Seek-time-first scheduling 

(B) small – small-time-first

(C) simple-seek-time-first 

(D) small-simple-time-first scheduling

Ans: (A)

Q.6 Before proceeding with its execution, each process must acquire all the resources it needs is called

(A) hold and wait 

(B) No pre-emption

(C) circular wait 

(D) starvation

Ans: (A)

Q.7 Virtual memory is

(A) simple to implement

(B) used in all major commercial operating systems

(C) less efficient in utilization of memory

(D) useful when fast I/O devices are not available

Ans: (B)

Q.8 Relocation bits used by relocating loader are specified by

(A) Relocating loader itself 

(B) Assembler or Translator

(C) Macro processor 

(D) Both (A) and (B)

Ans: (B)

Q.9 Resolution of externally defined symbols is performed by

(A) Linker 

(B) Loader

(C) Compiler 

(D) Editor

Ans: (A)

Q.10 Relocatable programs

(A) cannot be used with fixed partitions

(B) can be loaded almost anywhere in memory

(C) do not need a linker

(D) can be loaded only at one specific location

Ans: (B)

Q.11 Page stealing

(A) is a sign of efficient system

(B) is taking page frames other working sets

(C) should be the tuning goal

(D) is taking larger disk spaces for pages paged out

Ans: (B)

Q.12 The total time to prepare a disk drive mechanism for a block of data to be read from is its

(A) latency

(B) latency plus transmission time

(C) latency plus seek time

(D) latency plus seek time plus transmission time

Ans: (C)

Q.13 To avoid race condition, the maximum number of processes that may be

simultaneously inside the critical section is

(A) zero 

(B) one

(C) two 

(D) more than two

Ans: (B)

Q.14 The memory allocation scheme subject to “external” fragmentation is

(A) segmentation 

(B) swapping

(C) pure demand paging 

(D) multiple fixed contiguous partitions

Ans: (A)

Q.15 Page fault frequency in an operating system is reduced when the

(A) processes tend to the I/O-bound

(B) size of pages is reduced

(C) processes tend to be CPU-bound

(D) locality of reference is applicable to the process

Ans: (D)

Q.16 In which of the following page replacement policies Balady’s anomaly occurs?

(A) FIFO 

(B) LRU

(C) LFU 

(D) NRU

Ans: (A)

Q.17 Which of the following are language processors?

(A) Assembler 

(B) Compiler

(C) Interpreter 

(D) All of the above

Ans: (D)

Q.18 Virtual memory can be implemented with

(A) Segmentation 

(B) Paging

(C) None 

(D) all of the above

Ans: (D)

Q.19 Recognition of basic syntactic constructs through reductions, this task is performed by

(A) Lexical analysis 

(B) Syntax analysis

(C) Semantic analysis 

(D) Structure analysis

Ans: (B)

Q.20 A grammar for a programming language is a formal description of

(A) Syntax 

(B) Semantics

(C) Structure 

(D) Code

Ans: (C)

Q.21 ___________ is a technique of temporarily removing inactive programs from the memory of computer system

(A) Swapping 

(B) Spooling

(C) Semaphore 

(D) Scheduler

Ans: (A)

Q.22 ___________ is a technique of improving the priority of process waiting in Queue for CPU allocation

(A) Starvation 

(B) Aging

(C) Revocation 

(D) Relocation

Ans: (B)

Q.23 ________ is the time required by a sector to reach below read/write head.

(A) Seek Time 

(B) Latency Time

(C) Access time 

(D) None

Ans: (B)

Q.24 Which of the following is most general phase structured grammar?

(A) Context – Sensitive 

(B) Regular

(C) Context – Free 

(D) None of the above

Ans: (A)

Q.25 File record length

(A) Should always be fixed

(B) Should always be variable

(C) Depends upon the size of file

(D) Should be chosen to match the data characteristics.

Ans: (D)

Q.26 A public key encryption system

(A) Allows only the correct receiver to decode the data

(B) Allows only one to decode the transmission.

(C) Allows only the correct sender to decode the data.

(D) Does not encode the data before transmitting it.

Ans: (A)

Operating System MCQ

 Q.1 The “blocking factor” of a file is

(A) The number of blocks accessible to a file

(B) The number of blocks allocated to a file

(C) The number of logical records in one physical record

(D) None of the above

Ans: (C)

Q.2 Which of these is a component of a process precedence sequence?

(A) Process name 

(B) Sequence operator ‘;’

(C) Concurrency operator ‘,’ 

(D) All of the above

Ans: (D)

Q.3 Which amongst the following is valid syntax of the Fork and Join Primitive?

(A) Fork <label> 

(B) Fork <label>Join <var> Join <label>

(C) For <var> 

(D) Fork <var>Join <var> join <var>

Ans: (A)

Q.4 Nested Macro calls are expanded using the

(A) FIFO rule (First in first out) 

(B) LIFO (Last in First out)

(C) FILO rule (First in last out) 

(D) None of the above

Ans: (B)

Q.5 A parser which is a variant of top-down parsing without backtracking is

(A) Recursive Descend. 

(B) Operator Precedence.

(C) LL(1) parser. 

(D) LALR Parser.

Ans: (A)

Q.6 The expansion of nested macro calls follows

(A) FIFO rule. 

(B) LIFO rule.

(C) LILO rule. 

(D) priority rule.

Ans: (B)

Q.7 In a two-pass assembler, the task of the Pass II is to

(A) separate the symbol, mnemonic opcode and operand fields.

(B) build the symbol table.

(C) construct intermediate code.

(D) synthesize the target program.

Ans: (D)

Q.8 A linker program

(A) places the program in the memory for the purpose of execution.

(B) relocates the program to execute from the specific memory area allocated to it.

(C) links the program with other programs needed for its execution.

(D) interfaces the program with the entities generating its input data.

Ans: (C)

Q.9 Which scheduling policy is most suitable for a time-shared operating system

(A) Shortest-job First. 

(B) Elevator.

(C) Round-Robin. 

(D) First-Come-First-Serve.

Ans: (C)

Q.10 A critical section is a program segment

(A) which should run in a certain specified amount of time.

(B) which avoids deadlocks.

(C) where shared resources are accessed.

(D) which must be enclosed by a pair of semaphore operations, P and V.

Ans: (C)

Q.11 An operating system contains 3 user processes each requiring 2 units of resource

R .The minimum number of units of R such that no deadlocks will ever arise is

(A) 4. 

(B) 3.

(C) 5. 

(D) 6.

Ans: (A)

Q.12 Locality of reference implies that the page reference being made by a process

(A) will always be to the page used in the previous page reference.

(B) is likely to be the one of the pages used in the last few page references.

(C) will always be to one of the pages existing in memory.

(D)will always lead to a page fault.

Ans: (B)

Q.13 Which of these is not a part of Synthesis phase

(A) Obtain machine code corresponding to the mnemonic from the Mnemonics table

(B) Obtain address of a memory operand from the symbol table

(C) Perform LC processing

(D) Synthesize a machine instruction or the machine form of a constant

Ans: (C)

Q.14 The syntax of the assembler directive EQU is

(A) EQU <address space> 

(B) <symbol>EQU<address space>

(C) <symbol>EQU 

(D) None of the above

Ans: (B)

Q.15 The following features are needed to implement top down parsing

(A) Source string marker

(B) Prediction making mechanism

(C) Matching and Backtracking mechanism

(D) All of the above

Ans: (D)

Q.16 A macro definition consists of

(A) A macro prototype statement 

(B) One or more model statements

(C) Macro pre-processor statements 

(D) All of the above

Ans: (D)

Q.17 The main reason to encrypt a file is to ______________.

(A) Reduce its size 

(B) Secure it for transmission

(C) Prepare it for backup 

(D) Include it in the start-up sequence

Ans: (B)

Q.18 Which of the following is not a key piece of information, stored in single page table entry, assuming pure paging and virtual memory

(A) Frame number

(B) A bit indicating whether the page is in physical memory or on the disk

(C) A reference for the disk block that stores the page

(D) None of the above

Ans: (C)

Q.19 A UNIX device driver is

(A) Structured into two halves called top half and bottom half

(B) Three equal partitions

(C) Unstructured

(D) None of the above

Ans: (A)

Q.20 The following is not a layer of IO management module

(A) PIOCS (Physical Input Output Control System)

(B) LIOCS (Logical Input Output Control System)

(C) FS (File System)

(D) MCS (Management Control System)

Ans: (D)

Q.21 Which amongst the following is not a valid page replacement policy?

(A) LRU policy (Least Recently Used)

(B) FIFO policy (First in first out)

(C) RU policy (Recurrently used)

(D) Optimal page replacement policy

Ans: (C)

Q.22 Consider a program with a linked origin of 5000. Let the memory area allocated to it have the start address of 70000. Which amongst the following will be the value to be loaded in relocation register?

(A) 20000 

(B) 50000

(C) 70000 

(D) 90000

Ans: (None of the above choice in correct. )

Q.23 An assembly language is a

(A) low level programming language

(B) Middle level programming language

(C) High level programming language

(D) Internet based programming language

Ans: (A)

Q.24 TII stands for

(A) Table of incomplete instructions

(B) table of information instructions

(C) translation of instructions information

(D) translation of information instruction

Ans: (A)

Q.25 An analysis, which determines the syntactic structure of the source statement, is called

(A) Sementic analysis 

(B) process analysis

(C) Syntax analysis 

(D) function analysis

Ans: (C)

Q.26 Action implementing instruction’s meaning are a actually carried out by

(A) Instruction fetch

(B) Instruction decode

(C) instruction execution

(D) Instruction program

Ans: (C)