Computer System Structures Interview Questions Part3

24) Recursion or large arrays of local variables avoided by kernel programmers because The kernel stack is usually a limited resource. A stack overflow crashes the entire machine.
T/F
Answer: True
Exp: by def
Level:1


25) What is the purpose of system calls?
a) system calls allow user-level processes to request services of the operating system.
b) system calls acts as traps.
c) both a and b
d) none of the above
answer : a
Exp: by def
Level:1


26) What are the major activities of an operating system in regard to process management?
a. The creation and deletion of both user and system processes
b. The suspension and resumption of processes
c. The provision of mechanisms for process synchronization
d. The provision of mechanisms for process communication
e. The provision of mechanisms for deadlock handling

a) a,b,c
b) a,b,d
c) a,b,c,e
d) a,b,c,d,e
answer:d
Level:1

27) What are the major activities of an operating system in regard to memory management?
a. Keep track of which parts of memory are currently being used and by whom.
b. Decide which processes are to be loaded into memory when memory space becomes available.
c. Allocate and deallocate memory space as needed.
d. Interrupt processes when executing

1) a and b
2) a,b and c
3) a and c
4) Only c

Answer:2
Level:1

28) The major activities of an operating system in regard to secondary-storage management?
a) Free-space management.
b) Storage allocation.
c) Interrupt processes while executing
d) Disk scheduling.


1) a and b
2) a,b and c
3) a,b and d
4) Only c

Answer:3
Level:1




29) Which of the following are true regarding the command interpreter?
a) the command interpreter reads commands from the user or from a file of commands and executes them
b) command interpreter is subject to changes
c) acts as an interface between primary and secondary memory

1) a and b
2) a,b and c
3) a and c
4) Only a

. Answer:1
It reads commands from the user or from a file of commands
and executes them, usually by turning them into one or more system
calls. It is usually not part of the kernel since the command interpreter
is subject to changes.
Level:2

30) What system calls have to be executed by a command interpreter or shell in order to start a new process in unix?
a) fork
b) ps
c) fork followed by exec
d) none of the above
Answer:c
process. The fork call clones the currently executing process, while the exec call overlays a new process based on a different executable over the calling process.
Level:1


31) Which of the following are trueregarding system programs and system calls?
a) System programs can be thought of as bundles of useful
system calls.
b) system calls provide basic functionality to users so that users do not need to write their own programs to solve common problems.
c) system calls can be defined by the user

1) a and b
2) a,b and c
3) a,b and d
4) Only b

Answer:1
Level:2

32) What is the main advantage of the layered approach to system design?
a) the system is easier to debug and modify because changes affect only limited sections of the system rather than touching all sections of the operating system.
b) Information is kept only where it is needed and is accessible only within a defined and restricted area, so any bugs affecting that data must be limited to a specific module or layer. c) microkernel approach helps increases the degree of multiprogramming.

1) a,b,c
2) a,b
3) Only a
4) None

Answer: 2
Level:2

33) what are the services provided by an operating system.
a. Program execution.
b. I/O handling
c. File-system manipulation.
d. commmunications
e. error detection

a) a,b,c,d
b) b,c,d,e
c) a,b,c,d,e
d) b,c,e
Answer:c
Level:1

34) What are the main advantages of the microkernel approach to system design?

a) adding a new service does not require modifying the kernel
(b) it is more secure as more operations are done in user mode than in kernel mode
(c) microkernel approach helps increases the degree of multiprogramming.
d) a simpler kernel design and functionality typically results in a more reliable operating system.



1) a,b,d
2) b,c,d
3) a,b,c,d
4) Only a

Answer:1
Level:2

35) some systems store the operating system in firmware, and others on disk?
for PDAs,cellular telephones etc a disk with a file system may be not be available for the device.hence they are stored in firmaware.
T/F.
Answer: True
Level:2

36) How could a system be designed to allow a choice of operating systems to boot from? What would the bootstrap program need to do?
a) during boot-up, a special program (which we will call the boot manager) will determine which operating system to boot into.
b) the boot-strap loader will load the operating system selected at the start-up.
c) only a
d) both a and b.

Answer:c

Exp: Consider a system that would like to run both Windows
XP and three different distributions of Linux (e.g., RedHat, Debian, and
Mandrake). Each operating system will be stored on disk. During system
boot-up, a special program (which we will call the boot manager) will
determine which operating system to boot into. This means that rather
initially booting to an operating system, the boot manager will first run
during system startup. It is this boot manager that is responsible for
determining which system to boot into. Typically boot managers must
be stored at certain locations of the hard disk to be recognized during
system startup. Boot managers often provide the user with a selection of
systems to boot into; boot managers are also typically designed to boot
into a default operating system if no choice is selected
Level:2


37) The following are the secondary storage media.
1) Magnetic tapes
2) Magnetic disks
3) Ram
4) None

Answer: 1 and 2
Level:1

38) Which of the following are Non volatile storage devices
a) Magnetic Tapes
b) Main memory
c) Optical disk
d) Secondary Memory

1) a and b
2) a,b and c
3) a,b and d
4) Only c

Answer: 3
Level:1

39) Electronic disk, Main memory, Magnetic disk and Cache are volatile. True/False
Answer: False
Level:1

40) ______: a secondary storage device, which holds data in bulk and it, holds data in magnetic medium of the disk.
1) Hard disc
2) Compact disc
3) RAM
4) CPU Registers
Answer: 1
Level:1

41) A ________ is a secondary (optical) storage device.
1) Hard disc
2) Compact disc
3) RAM
4) CPU Register
Answer: 2
Level:1

42) ________ is the type of memory access in main memory (RAM).
1) Sequential access
2) DMA
3) Both
4) None
Answer: 2
Level:1

43) Which of the following is a volatile storage medium?
1) Hard disc
2) Cache
3) Magnetic tapes
4) Compact disc
Answer: 2
Level:1

44) The _________ is the additional time waiting for the disc to rotate the desired sector to the disc head
1) Rotational latency
2) Bandwidth
3) Seek time
4) None
Answer: 1
Level:1

45) ________: keep in memory only those instructions and data that are needed at any given time.
Needed when the process is larger than the amount of memory allocated to it.
1) Overlays
2) Studs
3) Cache
4) None
Answer: 1
Level:2

46) For Virtual memory implementation the OS uses ________
1) Compact disc
2) Floppy drives
3) Hard disc
4) Cache
Answer: 3
Level:2