Computer Science - Operating Systems
Exam Duration: 45 Mins Total Questions : 30
In real-time operating system, which of the following is the most suitable scheduling algorithm?
- (a)
Round-Robin
- (b)
FCFS
- (c)
Pre-emptive
- (d)
Random
Supervisor call
- (a)
ia a call made by the supervisor of the system
- (b)
is a call with control function
- (c)
is a call made by someone working in root directory
- (d)
None of the above
A state is safe if the system can allocate resources to each process in same order and still avoid deadlock. Then
- (a)
deadlock state is safe
- (b)
unsafe state may lead deadlock situation
- (c)
deadlock state is subset of unsafe state
- (d)
All of the above
A system has 3 processes sharing 4 resources. If each process need a maximum of 2 units, then
- (a)
deadlock can never occur
- (b)
deadlock may occur
- (c)
deadlock has to occur
- (d)
none of the above
m processes share n resources of sample type the maximum need of each process doesn't exceed n and the sum all their maximum need always less than m+n. In this set up
- (a)
deadlock can never occur
- (b)
deadlock may occur
- (c)
deadlock has to occur
- (d)
None of the above
The first fit best fit and worst-fit algorithm can be used for
- (a)
contiguous memory location
- (b)
linked allocation of memory
- (c)
index allocation of memory
- (d)
All of the above
A process has been allocated 3 page frames. Assume that none of the page of the process are available in the memory initially. The process makes the following sequence of page reference
1, 2, 1, 3, 7, 4, 5, 6, 3, 1
If optimal page replacement policy is used, how many page faults occur for above reference string
- (a)
7
- (b)
8
- (c)
9
- (d)
10
Feed back queue
- (a)
are very easy to implement
- (b)
dispatch tasks according to execution characteristics
- (c)
are used to favor real-time tasks
- (d)
require manual intervention to implement properly
Round-Robin scheduling is essentially the pre-emptive version of
- (a)
FIFO
- (b)
shortest job first
- (c)
shortest remaining
- (d)
longest time first
Which of the following will determine your choice of system software for your computer?
- (a)
Is the application software you want to use compatible with it
- (b)
Is it expensive
- (c)
Is compatible with you hardware
- (d)
Both (a) and (c)
What is a shell?
- (a)
It is a hardware component
- (b)
It is a command interpreter
- (c)
It is a part in compiler
- (d)
It is a tool in CPU scheduling
Multiprogramming systems
- (a)
are easier to develop than single programming systems
- (b)
execute each job faster
- (c)
execute more jobs in the same time
- (d)
are used only on large main frame computers
The problem of thrashing is effected scientifically by
- (a)
program structures
- (b)
program size
- (c)
primary storage size
- (d)
None of these
The mechanism that bring a page into memory only when it is needed is called
- (a)
segmentation
- (b)
fragmentation
- (c)
demand paging
- (d)
page replacement
A thread
- (a)
is a lightweight process where the context switching is low
- (b)
is a lightweight process where the context switching is high
- (c)
is used to speed up paging
- (d)
None of the above
The operating system manages
- (a)
memory
- (b)
processor
- (c)
disk and I/O device
- (d)
All of these
The hardware mechanism that enable a device to notify the CPU is called
- (a)
Polling
- (b)
interrupt
- (c)
system call
- (d)
None of these
Process state is a part of
- (a)
process control block
- (b)
incode
- (c)
file allocation table
- (d)
None of these
_____ page replacement algorithm suffers from Belady's anamoly.
- (a)
LRU
- (b)
MRU
- (c)
FIFO
- (d)
LIFO
A program at the time of executing is called
- (a)
dynamic program
- (b)
static program
- (c)
binded program
- (d)
a process
If you don't know which version of MS-DOS you are working with, which command will you use after booting your operating system?
- (a)
Format command
- (b)
FAT command
- (c)
VER command
- (d)
DISK command
A process said to be in ______ state if was waiting for an event that will never occur.
- (a)
sate
- (b)
unsafe
- (c)
starvation
- (d)
deadlock
Real-time system are
- (a)
primarily used on mainframe computers
- (b)
used for monitoring events as they occur
- (c)
used for program development
- (d)
used for real-time interactive users
A ______ contains information about the file, including ownership, permission and location of he file contents.
- (a)
File Control Block (FCB)
- (b)
file
- (c)
device drivers
- (d)
file system
The operating system of a computer serves as a software between the user and the
- (a)
hardware
- (b)
peripheral
- (c)
memory
- (d)
screen
DMA stands for
- (a)
Direct Memory Access
- (b)
Digital Memory Access
- (c)
Direct Main Access
- (d)
Digital Main Access
Which mechanism allows transferring data to and from memory without the interversion of the CPU?
- (a)
Automatic job sequencing
- (b)
Direct memory access
- (c)
Central processing unit
- (d)
Memory management
Which one is an example of multi-user operating system?
- (a)
MS-DOS
- (b)
Unix
- (c)
Windows 3.11
- (d)
Both (a) and (b)
FIFO stands for.........
- (a)
First In First Output
- (b)
First in First Out
- (c)
First Input First Output
- (d)
First Input First Out
By how many types does the operating system divides the main memory?
- (a)
2
- (b)
4
- (c)
3
- (d)
5