Operating System MCQ Set 1
1. A monitor is a type of :
a) semaphore
b) low level synchronization construct
c) high level synchronization construct
d) none of the mentioned
Answer
Answer: c [Reason:] None.
2. A monitor is characterized by :
a) a set of programmer defined operators
b) an identifier
c) the number of variables in it
d) all of the mentioned
Answer
Answer: a [Reason:] None.
3. A procedure defined within a ________ can access only those variables declared locally within the _______ and its formal parameters.
a) process, semaphore
b) process, monitor
c) semaphore, semaphore
d) monitor, monitor
Answer
Answer: d [Reason:] None.
4. The monitor construct ensures that :
a) only one process can be active at a time within the monitor
b) n number of processes can be active at a time within the monitor (n being greater than 1)
c) the queue has only one process in it at a time
d) all of the mentioned
Answer
Answer: a [Reason:] None.
5. The operations that can be invoked on a condition variable are :
a) wait & signal
b) hold & wait
c) signal & hold
d) continue & signal
Answer
Answer: a [Reason:] None.
6. The process invoking the wait operation is :
a) suspended until another process invokes the signal operation
b) waiting for another process to complete before it can itself call the signal operation
c) stopped until the next process in the queue finishes execution
d) none of the mentioned
Answer
Answer: a [Reason:] None.
7. If no process is suspended, the signal operation :
a) puts the system into a deadlock state
b) suspends some default process’ execution
c) nothing happens
d) the output is unpredictable
Answer
Answer: c [Reason:] None.
Operating System MCQ Set 2
1. In domain structure what is Access-right equal to ?
a) Access-right = object-name, rights-set
b) Access-right = read-name, write-set
c) Access-right = read-name, execute-set
d) Access-right = object-name, execute-set
Answer
Answer: a [Reason:] None.
2. What is meaning of right-set ?
a) It is a subset consist of read and write
b) It is a subset of all valid operations that can be performed on the object
c) It is a subset consist of read,write and execute
d) None of the mentioned
Answer
Answer: b [Reason:] None.
3. What is Domain ?
a) Domain = Set of all objects
b) It is a collection of protection policies
c) Domain= set of access-rights
d) None of the mentioned
Answer
Answer: c [Reason:] None.
4. What does access matrix represent ?
a) Rows-Domains, Columns-Objects
b) Rows-Objects, Columns-Domains
c) Rows-Access List, Columns-Domains
d) Rows-Domains, Columns-Access list
Answer
Answer: a [Reason:] None.
5. What are the three additional operations to change the contents of the access-matrix ?
a) copy
b) Owner
c) control
d) all of the mentioned
Answer
Answer: d [Reason:] None.
6. Who can add new rights and remove some rights ?
a) copy
b) transfer
c) limited copy
d) owner
Answer
Answer: d [Reason:] None.
7. What are the three copy rights ?
a) copy
b) transfer
c) limited copy
d) all of the mentioned
Answer
Answer: d [Reason:] None.
8. Which two rights allow a process to change the entries in a column ?
a) copy and transfer
b) copy and owner
c) owner and transfer
d) deny and copy
Answer
Answer: a [Reason:] None.
9. Which is an unsolvable problem in access-matrix ?
a) Owner override
b) Brute force
c) Access denied
d) Confinement
Answer
Answer: d [Reason:] None.
10. Which of the following objects require protection ?
a) CPU
b) Printers
c) Motherboard
d) All of the mentioned
Answer
Answer: b [Reason:] None.
11. What is ‘separation’ in security of Operating systems ?
a) To have separate login for different users
b) To have separate Hard disk drive/partition for different users
c) It means keeping one user’s objects separate from other users
d) None of the mentioned
Answer
Answer: c [Reason:] None.
12. Which of the following statements are correct?
i) Physical separation – in which process use different physical objects like separate printers
ii) Physical separation – in which process having different security requirement at different times
iii) Logical separation – In which users operate under illusion that no other processes exist
iv) Logical sepration – In which processes conceal their data and computations
a) i
b) i and iii
c) ii and iii
d) iii and iv
Answer
Answer: b [Reason:] None.
13. Which of the following statements are correct?
i) Physical separation – in which process use different physical objects like separate printers
ii) Temporal separation – in which process having different security requirement at different times
iii) Physical separation – In which users operate under illusion that no other processes exist
iv) Temporal sepration – In which processes conceal their data and computations
a) i
b) i and ii
c) ii and iii
d) iii and iv
Answer
Answer: b [Reason:] None.
14. Which of the following statements are correct?
i) logical separation – in which process use different physical objects like separate printers
ii) cryptographic separation – in which process having different security requirement at different times
iii) Logical separation – In which users operate under illusion that no other processes exist
iv) cryptographic sepration – In which processes conceal their data and computations
a) i
b) i and ii
c) ii and iii
d) iii and iv
Answer
Answer: d [Reason:] None.
15. What are various roles of protection ?
a) It is used to detect errors which can prevent contamination of system
b) It is used used to accelerate a process
c) It is used to optimize system downtime
d) None of the mentioned
Answer
Answer: a [Reason:] None.
16. Which of the following objects require protection ?
a) Memory
b) Monitor
c) Power supply unit
d) All of the mentioned
Answer
Answer: a [Reason:] None.
Operating System MCQ Set 3
1. What is true regarding ‘Fence’ ?
a) Its a method to confine users to one side of a boundary
b) It can protect Operating system from one user
c) It cannot protect users from each other
d) All of the mentioned
Answer
Answer: d [Reason:] None.
2. What is not true regarding ‘Fence’ ?
a) It is implemented via hardware register
b) It doesn’t protect users from each other
c) It good to protect OS from abusive users
d) Its implementation is unrestricted and can take any amount of space in Operating system.
Answer
Answer: d [Reason:] None.
3. What is correct regarding ‘relocation’ w.r.t protecting memory ?
a) It is a process of taking a program as if it began at address 0
b) It is a process of taking a program as if it began at address 0A
c) Fence cannot be used within relocation process
d) All of the mentioned
Answer
Answer: a [Reason:] None.
4. How can fence and relocation be used together ?
a) To each program address, the contents of fence register are added
b) To contents of fence register is subtracted from actual address of program
c) To each program address, the contents of fence register are not added
d) None of the mentioned
Answer
Answer: a [Reason:] This both relocates the address and guarantees that no one can access a location lower than a fence address.
5. What is basic need in protecting memory in multi-user environment ?
a) We need two registers one ‘start’ and other ‘end’
b) We need a variable register
c) A fence register has to be used known as base register.
d) None of the mentioned
Answer
Answer: c [Reason:] None.
6. What is role of base/bound registers ?
a) They give starting address to a program
b) Program’s addresses are neatly confined to space between the base and the bound registers
c) They provide encrypted environment
d) This technique doesn’t protects a program’s address from modification by another user
Answer
Answer: b [Reason:] None.
7. What is all-or-nothing situation for sharing in memory ?
a) Program makes all its data available to be accessed
b) It prohibits access to some
c) It creates rules who can access program memory
d) It separates program memory and data memory
Answer
Answer: a [Reason:] None.
8. How is disadvantage of all-or-nothing approach overcome ?
a) Base/Bound
b) Relocation technique
c) Fence method
d) Tagged architecture
Answer
Answer: d [Reason:] None.
9. What is true regarding tagged architecture ?
a) Every word of machine memory has one or more extra bits
b) Extra bits are used to do padding
c) Extra bits are not used to identify rights to that word
d) It is very compatible to code upgrades
Answer
Answer: a [Reason:] None.
10. What is best solution to have effect of unbounded number if base/bound registers?
a) Tagged architecture
b) Segmentation
c) Fence method
d) None of the mentioned
Answer
Answer: b [Reason:] None.
11. What is major feature of segmentation ?
a) Program is divided in data memory and program memory
b) Program is executed in segments
c) Program is divided into pieces having different access rights
d) It has effect of an unbounded architecture
Answer
Answer: c [Reason:] None.
12. What is correct way the segmentation program address is stored ?
a) name, offset
b) start, stop
c) access, rights
d) offset, rights
Answer
Answer: a [Reason:] OS can retrieve the real address via looking for the table then making a simple calculation : address of the name + offset.
13. What is main objective of protection ?
a) Ensure all objects are protected individually
b) Objects have different priority and thus different levels of protection
c) Ensure that each object is accessed correctly and only by allowed processes
d) None of the mentioned
Answer
Answer: c [Reason:] None.
14. What is principle of least privilege ?
a) Less privileges provide difficulty in executing admin tasks
b) Users can get temporary high privilege access
c) Users should be given just enough privileges to perform their tasks
d) None of the mentioned
Answer
Answer: c [Reason:] None.
15. What is need of protection ?
a) Prevent mischievous violation
b) Prevent and intentional
c) Ensure that each program component uses resources allotted to it only
d) All of the mentioned
Answer
Answer: d [Reason:] None.
Operating System MCQ Set 4
1. What is preferred way of encryption ?
a) pre shared secret key
b) using key distribution center (KDC)
c) public key-encryption
d) symmetric key
Answer
Answer: c [Reason:] Preshared key can be compromised and either party can be suspected. Likewise KDC or symmetric key can have breach which are undesirable. Public and private key encryption is a known industry standard.
2. What is not a role of encryption ?
a) It is used to protect data from unauthorized access during transmission
b) It is used to ensure user authentication
c) It is used to ensure data integrity
d) It is used to ensure data corruption doesn’t happens
Answer
Answer: d [Reason:] Encryption doesn’t have error correction or detection facility thus cannot be used to safeguard from data corruption.
3. What is cipher-block chaining ?
a) Data is logically ‘ANDed’ with previous block
b) Data is logically ‘ORed’ with previous block
c) Data is logically ‘XORed’ with previous block
d) None of the mentioned
Answer
Answer: c [Reason:] None.
4. What is not an encryption standard ?
a) AES
b) TES
c) Triple DES
d) DES
Answer
Answer: b [Reason:] None.
5. Which of following is not a stream cipher?
a) Two fish
b) RC5
c) RC4
d) TBONE
Answer
Answer: d [Reason:] None.
6. What is a Hash Function ?
a) It creates a small flexible block of data
b) It creates a small,fixed block of data
c) It creates a encrypted block of data
d) none of the mentioned
Answer
Answer: b [Reason:] None.
7. MD5 produces __ bits hash data.
a) 128
b) 150
c) 160
d) 112
Answer
Answer: a [Reason:] None.
8. SHA-1 produces __ bit of hash.
a) 128
b) 160
c) 150
d) 112
Answer
Answer: b [Reason:] None.
9. Which two of the following are authentication algorithms ?
a) MAC
b) AES
c) DAS
d) Digital-signature
Answer
Answer: a [Reason:] None.
10. What is role of Key Distribution Center ?
a) It is used to distribute keys to everyone in world
b) It intended to reduce the risks inherent in exchanging keys
c) all of the mentioned
d) none of the mentioned
Answer
Answer: b [Reason:] None.
Operating System MCQ Set 5
1. What are the different ways to intrude ?
a) Buffer overflows
b) Unexpected combinations and unhandled input
c) Race conditions
d) All of the mentioned
Answer
Answer: d [Reason:] None.
2. What are major components of intrusion detection system ?
a) Analysic Engine
b) Event provider
c) Alert Database
d) All of the mentioned
Answer
Answer: d [Reason:] None.
3. What are the different ways to classify an IDS ?
a) anomaly detection
b) signature based misuse
c) stack based
d) all of the mentioned
Answer
Answer: d [Reason:] None.
4. What are the different ways to classify an IDS ?
a) Zone based
b) Host & Network based
c) Network & Zone based
d) Level based
Answer
Answer: b [Reason:] None.
5. What are characteristics of anomaly based IDS ?
a) It models the normal usage of network as a noise characterization
b) It doesnt detect novel attacks
c) Anything distinct from the noise is not assumed to be intrusion activity
d) It detects based on signature
Answer
Answer: a [Reason:] None.
6. What is major drawback of anomaly detection IDS ?
a) These are very slow at detection
b) It generates many false alarms
c) It doesnt detect novel attacks
d) None of the mentioned
Answer
Answer: b [Reason:] None.
7. What are characteristics of signature based IDS ?
a) Most are based on simple pattern matching algorithms
b) It is programmed to interpret a certain series of packets
c) It models the normal usage of network as a noise characterization
d) Anything distinct from the noise is assumed to be intrusion activity
Answer
Answer: a [Reason:] None.
8. What are drawbacks of signature based IDS ?
a) They are unable to detect novel attacks
b) They suffer from false alarms
c) They have to be programmed again for every new pattern to be detected
d) All of the mentioned
Answer
Answer: d [Reason:] None.
9. What are characteristics of Host based IDS ?
a) The host operating system logs in the audit information
b) Logs includes logins,file opens and program executions
c) Logs are analysed to detect tails of intrusion
d) All of the mentioned
Answer
Answer: d [Reason:] None.
10. What are drawbacks of the host based IDS ?
a) Unselective logging of messages may increase the audit burdens
b) Selective logging runs the rish of missed attacks
c) They are very fast to detect
d) They have to be programmed for new patterns
Answer
Answer: a [Reason:] None.
11. What are strengths of the host based IDS ?
a) Attack verification
b) System specific acitvity
c) No addition hardware required
d) All of the mentioned
Answer
Answer: d [Reason:] None.
12. What are characteristics of stack based IDS ?
a) They are integrated closely with the TCP/IP stack and watch packets
b) The host operating system logs in the audit information
c) It is programmed to interpret a certain series of packets
d) It models the normal usage of network as a noise characterization
Answer
Answer: a [Reason:] None.
13. What are characteristics of Network based IDS ?
a) They look for attack signatures in network traffic
b) Filter decides which traffic will not be discarded or passed
c) It is programmed to interpret a certain series of packet
d) It models the normal usage of network as a noise characterization
Answer
Answer: a [Reason:] None.
14. What are strengths of Network based IDS ?
a) Cost of ownership reduced
b) Malicious intent detection
c) Real time detection and response
d) All of the mentioned
Answer
Answer: d [Reason:] None.
