A scheduling algorithm assigns priority proportional to the waiting time of a process. Every process starts with priority zero(the lowest priority). The scheduler re-evaluates the process priorities every T time units and decides the next process to schedule. Which one of the following is TRUE if the processes have no I/O operations and all arrive at time zero?

This algorithm is equivalent to the first-come-first-serve algorithm
This algorithm is equivalent to the round-robin algorithm
This algorithm is equivalent to the shortest-job-first algorithm
This algorithm is equivalent to the shortest-remaining-time-first algorithm
      _____________________________________________________________________________________
 A process executes the code
fork();
fork();
fork();


3
4
7
8
      _____________________________________________________________________________________
Memory utilization factor shall be computed as follows 

Memory in use/allocated memory
Memory in use/total memory connected
Memory allocated/total memory available
Memory committed/total memory available
      _____________________________________________________________________________________
Assume N segments in memory and a page size of P bytes. The wastage on account of internal fragmentation is

NP/2 bytes
P/2 bytes
N/2 bytes
NP bytes
      _____________________________________________________________________________________
Consider a logical address space of 8 pages of 1024 words mapped with memory of 32 frames. How many bits are there in the physical address ?

9 bits
11 bits
14 bits
15 bits
      _____________________________________________________________________________________
Moving process from main memory to disk is called 

Scheduling
Catching
Swapping
Spooling
      _____________________________________________________________________________________
Which of the following is the process by which a user’s access to physical data in the application is limited, based on his privileges ?

Authorization
Authentication
Access Control
All of these
      _____________________________________________________________________________________
Which of the following statements is not correct with reference to distributed systems ?

Distributed system represents a global view of the network and considers it as a virtual uniprocessor system by controlling and managing resources across the network on all the sites.
Distributed system is built on bare machine, not an add-on to the existing software.
In a distributed system, kernel provides smallest possible set of services on which other services are built. This kernel is called microkernel. Open servers provide other services and access to shared resources.
In a distributed system, if a user wants to run the program on other nodes or share the resources on remote sites due to their beneficial aspects, user has to log on to that site.
      _____________________________________________________________________________________
In the blocked state 

The processes waiting for I/O are found
The process which is running is found
The processes waiting for the processor are found
None of the above
      _____________________________________________________________________________________
Match the following :
(a) Disk scheduling      1. Round-robin
(b) Batch processing     2. SCAN
(c) Time sharing              3. LIFO
(d) Interrupt processing 4. FIFO


3   4   2   1
4   3   2   1
2   4   1   3
1   4   3   2
      _____________________________________________________________________________________
In which of the following page replacement policies Balady’s anomaly occurs? 

FIFO
LRU
LFU
NRU
      _____________________________________________________________________________________
The simplest way to break a deadlock is to 

Preempt a resource
Rollback
Kill one of the processes
Lock one of the processes
      _____________________________________________________________________________________
Three concurrent processes X, Y, and Z execute three different code segments that access and update certain shared variables. Process X executes the P operation (i.e., wait) on semaphores a, b and c; process Y executes the P operation on semaphores b, c and d; process Z executes the P operation on semaphores c, d, and a before entering the respective code segments. After completing the execution of its code segment, each process invokes the V operation (i.e., signal) on its three semaphores. All semaphores are binary semaphores initialized to one. Which one of the following represents a deadlock- free order of invoking the P operations by the processes?

X : P (a ) P (b) P (c ) Y : P (b ) P (c) P (d) Z : P (c ) P (d) P (a)
X : P (b ) P (a) P (c ) Y : P (b ) P (c) P (d)  Z : P (a ) P (c ) P (d)
X : P (b ) P (a) P (c ) Y : P (c ) P (b) P (d) Z : P (a ) P (c ) P (d)
X : P (a ) P (b) P (c ) Y : P (c ) P (b) P (d) Z : P (c ) P (d) P (a)
      _____________________________________________________________________________________
A relationship between processes such that each has some part (critical section) which must not be executed while the critical section of another is being executed, is known as

Semaphore
Mutual exclusion
Multiprogramming
Message passing
      _____________________________________________________________________________________
Which of the following topologies consists of multiple CPUs connected by a single communication line running the length of the network? 

Tree
Ring
Star
Bus
      _____________________________________________________________________________________
An operating system 

Is not required on large computers
Is always supplied with the computer
Is always supplied with the BASIC
Consists of programs that help in the operation of computer
      _____________________________________________________________________________________
The operating system of a computer serves as a software interface between the user and

Software
Hardware
Processor
Compiler
      _____________________________________________________________________________________
In one time password

The password is different in each instance
The password is same in each instance
Both A and B
None of these
      _____________________________________________________________________________________
Interval between the time of submission and completion of job is called 

Waiting time
Turn around time
Throughput
Response time
      _____________________________________________________________________________________
 In the process management Round-robin method is essentially the pre-emptive version of _________

FILO
FIFO
SSF
Longest time first
      _____________________________________________________________________________________
System supports two types of file which are

Text files
Executable binary files
Both a and b
None of these
      _____________________________________________________________________________________


There is no change.
Average cohesion goes up but coupling is reduced.
Average cohesion goes down and coupling also reduces.
Average cohesion and coupling increase.
      _____________________________________________________________________________________
In virtual memory systems, Dynamic address translation 

Is the hardware necessary to implement paging
Stores pages at a specific location on disk
Is useless when swapping is used
Is part of the operating system paging algorithm
      _____________________________________________________________________________________
Which of the following is not supported by the operating system? 

Protection
Accounting
Compilation
I/O operation
      _____________________________________________________________________________________
Memory on your computer where data is stored temporarily is called __________. 

RAM
ROM
BIOS
CPU
      _____________________________________________________________________________________

A process executes the code

fork ();
fork ();
fork ();
fork ();
The total number of child processes created is


7
9
31
15
      _____________________________________________________________________________________
The multiuser operating system, 20 requests are made to use a particular resource per hour, on an average the probability that no request are made in 45 minutes is

e-15
e-5
1 – e-5
1 – e-10
      _____________________________________________________________________________________
Dijkstra banker algorithm is an operating system to solve the problem of

dead look avoidance
dead look recovery
mutual exclusion
contest sustaining
      _____________________________________________________________________________________
Pre-emptive scheduling is the strategy of temporarily suspending a gunning process

before the CPU time slice expires
to allow starving processes to run
when it requests I/O
to avoid collision
      _____________________________________________________________________________________
Consider a hard disk with 16 recording surfaces (0 -15) having 16384 cylinders (0 -16383) and each cylinder contains 64 sectors (0 - 63) . Data storage capacity in each sector is 512 bytes. Data are organized cylinder–wise and the addressing format is <cylinder no., sector no.>. A file of size 42797 KB is stored in the disk and the starting disk location of the file is <1200, 9, 40>. What is the cylinder number of the last sector of the file, if it is stored in a contiguous manner?

1281
1282
1283
1284
      _____________________________________________________________________________________
The hit ratio of a Translation Look Aside Buffer (TLAB) is 80%. It takes 20 nanoseconds (ns) to search TLAB and 100 ns to access main memory. The effective memory access time is

36 ns
140 ns
122 ns
40 ns
      _____________________________________________________________________________________
A thread 

Is a lightweight process where the context switching is low
Is a lightweight process where the context switching is high
Is used to speed up paging
None of the above
      _____________________________________________________________________________________
File attributes are

Name
Type
Location
All of these
      _____________________________________________________________________________________
Which is built directly on the hardware? 

Computer Environment
Application Software
Operating System
Database System
      _____________________________________________________________________________________
A solution to the critical section problem must satisfy which requirements? 

Bounded waiting, monitor and relative speed
Semaphores, monitor and prevention of deadlock
Signal, wait and continue
Mutual exclusion, progress and bounded waiting
      _____________________________________________________________________________________
______ is used in operating system to separate mechanism from policy 

Single level implementation
Two level implementation
Multi level implementation
None
      _____________________________________________________________________________________
Worm was made up

One program
Two program
Three program
All of these
      _____________________________________________________________________________________
Given memory partitions of 100K, 500K, 200K, 300K and 600K (in order) and processes of 212K, 417K, 112K, and 426K (in order), using the first-fit algorithm in which partition would the process requiring 426K be placed? 

100K
500K
200K
600K
      _____________________________________________________________________________________
The primary purpose of an operating system is 

To make the most efficient use of the computer hardware
To allow people to use the computer
To keep systems programmers employed
To make computers easier to use
      _____________________________________________________________________________________
Let the page fault service time be 10  millisecond(ms) in a computer with average memory access time being 20 nanosecond(ns). If one page fault is generated for every 106 memory accesses, what is the effective access time for memory ?

21 ns
23 ns
30 ns
35 ns
      _____________________________________________________________________________________
A tree structured file directory system 

Allows easy storage and retrieval of file names
Is a much debated unnecessary feature
Is not essential when we have millions of files
None of the above
      _____________________________________________________________________________________
Security violation due to 

Malicious
Accidental
Both A and B
None of these
      _____________________________________________________________________________________
Multiprogramming systems 

Are easier to develop than single programming systems
Execute each job faster
Execute more jobs in the same time period
Are used only one large mainframe computers
      _____________________________________________________________________________________
The most common approach to authenticating a user identity is 

User password
User log in
Hardware device
None of these
      _____________________________________________________________________________________
A starvation-free job-scheduling policy guarantees that no job waits indefinitely for service. Which of the following job-scheduling policies is starvation-free?

Round-robin
Priority queuing
Shortest job first
Youngest job first
      _____________________________________________________________________________________
Which of the following statement is wrong ?
I. 2-phase locking protocol suffer from dead lock.
II. Time stamp protocol suffer from more aborts.
III. A block hole in a DFD is a data store with only inbound flows.
IV. Multivalued dependency among attribute is checked at 3 NF level.
V. An entity-relationship diagram is a tool to represent event model.


I, II, II
II, III, IV
III, IV, V
II, IV, V
      _____________________________________________________________________________________
Remote Computing Service involves the use of time sharing and _______.

multi-processing
interactive processing
batch processing
real-time processing
      _____________________________________________________________________________________
Cascading termination refers to termination of all child processes before the parent terminates 

Normally
Abnormally
Normally or abnormally
None of these
      _____________________________________________________________________________________
In round robin CPU scheduling as time quantum is increased the average turn around time

increases
decreases
remains constant
varies irregularly
      _____________________________________________________________________________________
At intermediate multiprogramming levels, the rate of increase of throughput with multiprogramming levels decreases. This phenomenon is best explained by the fact that as multiprogramming level increases

I/O activities per request remains constant
Some system resources begins to saturate (i.e., to be utilized 100%)
The utilization of memory improves
The average time spent in the system by each request increases
      _____________________________________________________________________________________
 
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