Computer Science and Information Technology - Operating System
Exam Duration: 45 Mins Total Questions : 30
Supervisor call
- (a)
is a call made by the supervisor of the system
- (b)
is a call with a control functions
- (c)
are pixilated calls that are used to perform resource management functions which controlled by the operating system
- (d)
in a call made by someone working in root directory
Some computer system supports dual mode operations, the user mode and the supervisor mode. These refers to the modes
- (a)
by which user program handle their data
- (b)
by which operating system executes its program
- (c)
in which the processor and the associated hardware operate
- (d)
of memory access
In Round-Robin CPU scheduling, as the time quantum is increased, the average turn around time
- (a)
increases
- (b)
decreases
- (c)
remains constant
- (d)
varies irregularly
Which of the following statements is true?
1. Shortest remaining time first scheduling may cause starvation
2. Pre-emptive scheduling may cause starvation
3. Round-Robin is better than FCFS in terms of response time
- (a)
1 only
- (b)
1 and 3
- (c)
2 and 3
- (d)
1, 2 and 3
A binary semaphore
- (a)
has the values one to zero
- (b)
is essential to binary computers
- (c)
is used only for synchronization
- (d)
is used only for mutual exclusion
Consider the following statements with respect to user clever threads and kernel with kernal supported threads:
1. Context switch is faster with Kernal supported threads
2. For user-level threads, a system call can block the entire process
3. Kernal supported threads can be scheduled independently
4. User level threads are transparent to the kernal.
Which of the above statement is true?
- (a)
1, 2, 4
- (b)
2, 3
- (c)
1 and 3
- (d)
1 and 2
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
In a page segment scheme of memory management, the segment table itself must have a page table because
- (a)
the segment is spread over a number to hit in one page
- (b)
each segment is spread over a number of pages
- (c)
segment table points to page tables and not to the physical location of the segments
- (d)
the processor's description base register points to a page table
The mechanism that brings a page into memory only when it is needed is called
- (a)
segmentation
- (b)
fragmentation
- (c)
demand paging
- (d)
page replacement
The simple directly structure is
- (a)
single level directory
- (b)
two level directory
- (c)
tree level directory
- (d)
None of the above
Disadvantage of single level directory is
- (a)
the confusion of file name between different users
- (b)
the confusion of file data
- (c)
Both (a) and (b)
- (d)
None of the above
There are no cycle in which type of directory
- (a)
general graphic directory
- (b)
a cyclic graph directory
- (c)
one level directory
- (d)
two level directory
Access time is highest in case of
- (a)
floppy disk
- (b)
cache
- (c)
swapping device
- (d)
magnetic disks
A page fault occurs
- (a)
when the page is not in the memory
- (b)
when the page is in the memory
- (c)
when the process enters the blocked state
- (d)
when the process is in the ready state
Let S and Q be two semaphores initialized to 1, where P0 and P1 processes the following statements wait (S); wait(Q);...; signal (S); signal (Q) and wait (Q); wait (S);...; signal (Q); signal (S); respectively. The above situation depicts a
- (a)
semaphore
- (b)
deadlock
- (c)
signal
- (d)
interrupt
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 number of processes completed per unit time is known as
- (a)
output
- (b)
throughout
- (c)
efficiency
- (d)
capacity
Which techniques was introduced because a single job could not keep both the CPU and the I/O device busy?
- (a)
Time sharing
- (b)
spooling
- (c)
pre-emptive scheduling
- (d)
Multiprogramming
A critical region
- (a)
is a piece of code which only one process executes at a time
- (b)
is a region prone to deadlock
- (c)
is a piece of code which only a finite number of processes execute
- (d)
is found only in Windows NT operating system
PCB is stands for
- (a)
Program Control Block
- (b)
Process Control Block
- (c)
Process Communication Block
- (d)
None of the above
FIFO scheduling is
- (a)
pre-emptive scheduling
- (b)
non-preemptive scheduling
- (c)
deadline scheduling
- (d)
fair share scheduling
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
______ begins at the root and follows a path down to the specified file
- (a)
relative path name
- (b)
absolute path name
- (c)
standalone name
- (d)
All of these
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
The removal of process from active contention of CPU and re-introduced them into memory later is
- (a)
interrupt
- (b)
swapping
- (c)
signal
- (d)
thread
The problem of thrashing is effected scientifically by
- (a)
program structure
- (b)
program size
- (c)
primary storage size
- (d)
None of these
A thread is a _______ process.
- (a)
heavy weight
- (b)
multiprocess
- (c)
inter thread
- (d)
light weight
______ allocates the largest hole available in the memory.
- (a)
Best fit
- (b)
Worst fit
- (c)
First fit
- (d)
None of these
The term Operating System means
- (a)
a set of programs which controls computer working
- (b)
the way a computer operating works
- (c)
conversion of high level into machine level language
- (d)
the way a floppy disk drive operates