UNIVERSITY EXAMINATIONS: 2017/2018
EXAMINATION FOR THE DEGREES OF BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY/ SOFTWARE DEVELOPMENT/
BUSINESS IT/ INFO. SEC& FORENSICS/ APPLIED COMPUTING
BAC 1102/ BISF 1102/ BSD 1104/ BIT 1106A/ BBIT 111: OPERATING
SYSTEMS
FULLTIME/ PART TIME/DISTANCE LEARNING
ORDINARY EXAMINATIONS
DATE: AUGUST, 2018 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [30 MARKS]
a) Define the term ‘operating system’ (2 Marks)
b) Give SIX types of operating systems (6 Marks)
c) Give SIX functions of the operating system (6 Marks)
d) Define a shell as used in operating system (3 Marks)
e) State the functions of a file manager (3 Marks)
f) Draw the structure of the MS-DOS operating system and briefly explain it. (5 Marks)
g) In your opinion why is Linux operating system emerging as an Operating system to reckon
over its rival Microsoft windows? Discuss. (5 Marks)
QUESTION TWO [20 MARKS]
a) Describe briefly the ways that can be used to terminate a process. (4 Marks)
b) What is a control structure that the operating system uses to keep the information
of the process context? Give the pieces of information that are likely to be in this
structure. (4 Marks)
c) i) What is a binary semaphore? (2 Marks)
ii) Describe the signal and wait operation and how it is implemented in a
semaphore. (4 Marks)
d) i) Explain what a thread is? Give an example. (2 Marks)
ii) What is the difference between a process and a thread? (4 Marks)
QUESTION THREE [20 MARKS]
a) Distinguish between the following pairs of terms:
i) Starvation and deadlock (2 Marks)
ii) Fault avoidance and error detection (2 Marks)
iii) Device driver and device controller (2 Marks)
iv) Paging and segmentation (2 Marks)
b) i) Describe the operations of shortest job first (SJF) and shortest remaining time
first (SRTF) scheduling algorithms. (4 Marks)
ii) Consider the following schedule. Complete the schedule for each of the two
algorithms in b(i) above
(8 Marks)
QUESTION FOUR [20 MARKS]
a) With the aid of a diagram, explain the relationship between operating system,
computer hardware, utility programs and application programs (6 Marks)
b) Briefly explain FOUR main performance criteria used to select a scheduling
algorithm (4 Marks)
c) i) Briefly describe any TWO file management metaphors (2 Marks)
ii) Identify and briefly describe any filename extensions (4 Marks)
d) Describe the FOUR conditions for deadlock in Operating System. (4 Marks)
QUESTION FIVE [20 MARKS]
a) i) Explain briefly the objective of computer security. (2 Marks)
ii) State three procedure and processes that specify security policies. (3 Marks)
iii) What does data integrity entail? Discuss (3 Marks)
b) Explain briefly the following terms with respect to inter-process synchronization
i) Critical section
ii) Mutual exclusion (4 Marks)
c) Describe the THREE forms of explicit inter-process synchronization (6 Marks)
d) Describe TWO ways in which a program can invoke services of the operating
system. (2 Marks)
