UNIVERSITY EXAMINATIONS: 2016/2017
EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY /BACHELOR OF BUSINESS
INFORMATION TECHNOLOGY /BACHELOR OF APPLIED
COMPUTING
BIT 1106A, BBIT 111, BCT 1101: OPERATING SYSTEMS
FULL TIME/PART TIME/DISTANCE LEARNING
DATE: AUGUST, 2017 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTION ONE [30 MARKS]
a) Briefly explain the following
i) Kernel (2 Marks)
ii) Thrashing (2 Marks)
iii) Polling (2 Marks)
iv) Stream (2 Marks)
b) Define interrupts and explain the sources of interrupts in OS (4 Marks)
c) Discuss the characteristics of modern operating systems. (5 Marks)
d) Explain FOUR concepts of virtual machine architecture (8 Marks)
e) Describe the factors to consider when selecting a file design method. (5 Marks)
QUESTION TWO [20 MARKS]
a) Give the states that a process can be in. (2 Marks)
b) Briefly explain four reasons for process switch. (8 Marks)
c) What is the function of the ready queue? (2 Marks)
d) What is the relationship between threads and processes (4 Marks)
e) What is a race condition? Give an example in an operating system. (4 Marks)
QUESTION THREE [20 MARKS]
a) Explain the difficulties with Concurrency. (4 Marks)
b) Discuss the conditions for Deadlock (8 Marks)
c) Describe the strategies to overcome deadlock ones it is Detected. (8 Marks)
QUESTION FOUR [20 MARKS]
a) Identify and explain any two fetch algorithms. (4 Marks)
b) Discuss seven (7) services provided by the Operating System (7 Marks)
c) Briefly explain the functions of O.S Kernel in process management (6 Marks)
d) Explain the role the PCB plays during interrupt handling. (3 Marks)
QUESTION FIVE [20 MARKS]
a) Explain the following memory allocation schemes
i) Contiguous allocation (2 Marks)
ii) Segmentation (2 Marks)
b) List four operations that are associated with files (4 Marks)
c) Explain two approaches that can be used to store files in a disk pointing out advantages and
disadvantages of each. (8 Marks)
d) Describe the information, which would be stored in a typical directory system pertaining to
the file within the directory. (4 Marks)
