Operating Systems

Question 1

What is software?

Answer 1

a collection of electronically stored instructions (a program) that allows you to interact with a computer

Question 2

What are the two software categories?

Answer 2

application software and system software

Question 3

What are some examples of application software?

Answer 3

office suites, photo editors (GIMP), web browsers (chrome), video conferencing (zoom, skpye)

Question 4

What are some examples of system software?

Answer 4

operating systems (windows, linux), antimalware (trend micro anti-virus)

Question 5

What is the role of a operating system?

Answer 5

process management, memory management, device management

Question 6

What is involved in process management?

Answer 6

managing numerous, concurrently running programs, managing the CPU through individual processes

Question 7

What is involved in memory management?

Answer 7

allocating and efficiently tracking memory

Question 8

What is involved in device management?

Answer 8

granting and sharing access to computer’s hardware

Question 9

What are the different process states?

Answer 9

ready, waiting, running, new, terminated

Question 10

What is PCB?

Answer 10

process control block is a data structure used by the OS to manage info about a process, including the current values of program counter, CPU register, and accounting info

Question 11

When is a new PCB created?

Answer 11

when a process is first created and persists until the process is terminated

Question 12

When a process moves from one state to another what happens to its corresponding PCB?

Answer 12

moves from one state list to another in the OS

Question 13

What happens each time a process is moved to the running state?

Answer 13

register values for the currently running process are stored into its PCB, the PCB is moved to the list of the state its going into, the register values of the new running process are loaded into the CPU

Question 14

What is the exchange of register values called? (running state)

Answer 14

context switch

Question 15

What is CPU scheduling?

Answer 15

the act of determining which process that is in the ready state should be moved to the running state

Question 16

How many processes can be in the running state? What about ready state?

Answer 16

only one, multiple

Question 17

What is non preemptive scheduling?

Answer 17

when the current executing process gives up the CPU voluntarily

Question 18

What is preemptive scheduling?

Answer 18

when the operating system decides to favour another process, prempting the currently executing process

Question 19

What is turn around time?

Answer 19

the amount of time between when a process arrives in the ready state the first time, and when it exits the running state for the last time

Question 20

What are some examples of CPU scheudling algorithms?

Answer 20

first come first serve, shortest job next, round robin

Question 21

What is first come first serve?

Answer 21

when processes are moved in the CPU in the order in which they arrive in the ready state

(first that arrives it the first moved into CPU)

Question 22

What is shortest job next?

Answer 22

the process with the shortest estimated running time in the ready state is moved to the running state

Question 23

What is round robin?

Answer 23

when process runs or a specific amount of time and then moves back to the ready state if not finished and the process repeats

Question 24

Which CPU scheduling algorithms are non-preemptive vs preemptive?

Answer 24

FCFS-non-preemptive
SJN-non-preemptive
RR-preemptive

Question 25

What is the problem with shortest job next?

Answer 25

the time each process will take is not known in advance so it has to check

Question 26

Which CPU scheduling algorithm has the shortest turn around time?

Answer 26

shortest job next

Question 27

What are files?

Answer 27

containers for data or related information, can be text or other binary data

Question 28

What are file extensions?

Answer 28

the suffix after a filename

Question 29

Does changing the extension automatically change the files format?

Answer 29

no, the extension does not guarantee that the contents conform to that file type

Question 29

Does changing the extension automatically change the files format?

Answer 29

no, the extension does not guarantee that the contents conform to that file type

Question 30

What are some document file extension examples?

Answer 30

.docx, .xlsx, .pptx, .ods, .odt, .odp

Question 31

What are some examples of text based file extensions?

Answer 31

.txt, .c, .html, .java, .xml, .css

Question 32

What are some examples of image file extensions?

Answer 32

.gif, .jpeg, .png, .svg,.tiff, .bmp

Question 33

What are some examples of media file extensions?

Answer 33

.wav, .mp3, .mkv, .mp4, .divx, .avi

Question 34

What are directories?

Answer 34

they contain files and/or other directories

ex. folders in file

Question 35

What is a directory tree?

Answer 35

a logical, tree diagram view of a file system

Question 36

What are the parts of a directory tree?

Answer 36

root directory (highest level in file system)

subdirectory (contained within another directory)

parent directory (contains subdirectory)

working directory (location you are viewing/working on)

Question 37

What is a file path?

Answer 37

the textual description of the location of a file or directory in a file system

Question 38

What is the absolute path vs relative path?

Answer 38

path from the root of the file system to the file/directory vs path from the working directory to the file/directory