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University of Science and Technology
Faculty of Computer Science and Information Technology
Midterm Exam -Fourth Year-B.Ss. Information Technology
Subject- Operating systems Concepts
NAME : ……………………………………………………………………………………..
STUDENT NUMBER : …………………………………………………………………….
_____________________________________
Allowable Time:1 hour
Answer All Questions
Question
1
2
3
Total
Question 1:(10 Marks)
1-Indicate whether the sentence or
Marks
statement is true (T) or false (F).
______ (a). Throughput is the time
measured till the process has a first output.
______ (b). Android is an embedded operating system.
______ (c) SJN is preemptive scheduling algorithm.
______ (d) When the computer is powered on, certain operating system
files load from a storage device such as a hard disk into RAM. This is
called bootstrapping .
______ (e). Windows API is known with POSIX API.
______ (f). Privilege process is a process working in the kernel .
______ (g). Dispatcher is responsible for removing a process from CPU and
replacing with another process .
______ (h). When child process is killed that means the parent also is killed.
______ (i). Compilers ,interpreters software represent what is called utility
software .
______ (j). Multiprogramming is an operating system which has a high
response for an emergent event.
Question 2:(20 Points)
1- Answer the following questions:
(a) What is an operating system? What are their types? And List six (6)
different names of an existing operating systems.
(4 Marks)
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(b)For each of the following pairs of terms, define each term, making sure to
clarify the key difference(s) between the two terms.
(6 Marks)
(i) “Round Robin” and “FCFS” scheduling algorithm
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(ii) “Multiprogramming” and “Multicomputer” operating systems
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(c) What is PCB ?
(2 Marks)
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(d) List six services provided by OS that are designed to make it more
convenient for user to use.
(6 Marks)
1-……………………………………..…… 2………..……………………………….
3…………………………………………... 4………………..……………………….
5……………………………………….….. 6………………..……………………….
(e)List in order of speed of access (fastest = 1).
(2 Marks)
_____ magnetic tape
_____ disk
_____ cache
_____ main memory
_____ register
Question 3:(15 Points)
(1) Consider the following set of jobs to be scheduled for execution on a single CPU
system.
Job
At
Pt
Wt
Dt
Wt/Pt
Ql
J1
0
10
J2
2
8
J3
3
3
J4
7
4
J5
10
1
J6
13
4
(a)-Draw a Gantt chart showing Round Robin scheduling if (q=2) and then fill the
above table .
(8 Marks)
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(b)-What is happened if (q=10)?
(2 Marks)
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(c)-compute AQL ,
AWt
(2 Marks)
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(c) What happens in a context switching?
(3 Marks)
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Good Luck
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