Category: Operating System Objective Questions

Operating System Multiple Choice Questions on “Monitors”.

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: c

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: a

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: d

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: a

5. What are the operations that can be invoked on a condition variable?
a) wait & signal
b) hold & wait
c) signal & hold
d) continue & signal

Answer: a

6. Which is the process of invoking the wait operation?
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: a

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: c

Tricky Operating System Questions and Answers on “I/O System – Application I/O Interface”.

1. The ________ can be turned off by the CPU before the execution of critical instruction sequences that must not be interrupted.
a) nonmaskable interrupt
b) blocked interrupt
c) maskable interrupt
d) none of the mentioned

Answer: c
Clarification: None.

2. The __________ is used by device controllers to request service.
a) nonmaskable interrupt
b) blocked interrupt
c) maskable interrupt
d) none of the mentioned

Answer: c
Clarification: None.

3. The interrupt vector contains ____________
a) the interrupts
b) the memory addresses of specialized interrupt handlers
c) the identifiers of interrupts
d) the device addresses

Answer: b
Clarification: None.

4. Division by zero, accessing a protected or non existent memory address, or attempting to execute a privileged instruction from user mode are all categorized as ________
a) errors
b) exceptions
c) interrupt handlers
d) all of the mentioned

Answer: b
Clarification: None.

5. For large data transfers, _________ is used.
a) dma
b) programmed I/O
c) controller register
d) none of the mentioned

Answer: a
Clarification: None.

6. A character stream device transfers ____________
a) bytes one by one
b) block of bytes as a unit
c) with unpredictable response times
d) none of the mentioned

Answer: a
Clarification: None.

7. A block device transfers ____________
a) bytes one by one
b) block of bytes as a unit
c) with unpredictable response times
d) none of the mentioned

Answer: b
Clarification: None.

8. What is a dedicated device?
a) opposite to a sharable device
b) same as a sharable device
c) can be used concurrently by several processes
d) none of the mentioned

Answer: a
Clarification: None.

9. A keyboard is an example of a device that is accessed through a __________ interface.
a) block stream
b) set of blocks
c) character stream
d) none of the mentioned

Answer: c
Clarification: None.

10. In polling ____________
a) busy – wait cycles wait for I/O from device
b) interrupt handler receives interrupts
c) interrupt-request line is triggered by I/O device
d) all of the mentioned

Answer: a
Clarification: None.

11. A non blocking system call _________________
a) halts the execution of the application for an extended time
b) does not halt the execution of the application
c) does not block the interrupts
d) none of the mentioned

Answer: b
Clarification: None.

12. An asynchronous call ____________
a) returns immediately, without waiting for the I/O to complete
b) does not return immediately and waits for the I/O to complete
c) consumes a lot of time
d) is too slow

Answer: a

Operating System Multiple Choice Questions on “Security – Intrusion Detection”.

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: d

2. What are the major components of the intrusion detection system?
a) Analysis Engine
b) Event provider
c) Alert Database
d) All of the mentioned

Answer: d

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: d

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: b

5. What are the characteristics of anomaly based IDS?
a) It models the normal usage of network as a noise characterization
b) It doesn’t detect novel attacks
c) Anything distinct from the noise is not assumed to be intrusion activity
d) It detects based on signature

Answer: a

6. What is the major drawback of anomaly detection IDS?
a) These are very slow at detection
b) It generates many false alarms
c) It doesn’t detect novel attacks
d) None of the mentioned

Answer: b
Clarification: None.

7. What are the 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: a
Clarification: None.

8. What are the 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: d
Clarification: None.

9. What are the 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: d
Clarification: None.

10. What are the drawbacks of the host based IDS?
a) Unselective logging of messages may increase the audit burdens
b) Selective logging runs the risk of missed attacks
c) They are very fast to detect
d) They have to be programmed for new patterns

Answer: a
Clarification: None.

11. What are the strengths of the host based IDS?
a) Attack verification
b) System specific activity
c) No additional hardware required
d) All of the mentioned

Answer: d
Clarification: 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: a
Clarification: 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: a
Clarification: 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: d

Operating System Multiple Choice Questions on “File System Concepts”.

1. ______ is a unique tag, usually a number identifies the file within the file system.
a) File identifier
b) File name
c) File type
d) None of the mentioned

Answer: a

2. To create a file ____________
a) allocate the space in file system
b) make an entry for new file in directory
c) allocate the space in file system & make an entry for new file in directory
d) none of the mentioned

Answer: c

3. By using the specific system call, we can ____________
a) open the file
b) read the file
c) write into the file
d) all of the mentioned

Answer: d

4. File type can be represented by ____________
a) file name
b) file extension
c) file identifier
d) none of the mentioned

Answer: b

5. Which file is a sequence of bytes organized into blocks understandable by the system’s linker?
a) object file
b) source file
c) executable file
d) text file

Answer: a
Clarification: None.

6. What is the mounting of file system?
a) crating of a filesystem
b) deleting a filesystem
c) attaching portion of the file system into a directory structure
d) removing the portion of the file system into a directory structure

Answer: c
Clarification: None.

7. Mapping of file is managed by ____________
a) file metadata
b) page table
c) virtual memory
d) file system

Answer: a
Clarification: None.

8. Mapping of network file system protocol to local file system is done by ____________
a) network file system
b) local file system
c) volume manager
d) remote mirror

Answer: a
Clarification: None.

9. Which one of the following explains the sequential file access method?
a) random access according to the given byte number
b) read bytes one at a time, in order
c) read/write sequentially by record
d) read/write randomly by record

Answer: b
Clarification: None.

10. When will file system fragmentation occur?
a) unused space or single file are not contiguous
b) used space is not contiguous
c) unused space is non-contiguous
d) multiple files are non-contiguous

Answer: a

Operating System Multiple Choice Questions on “Disk Scheduling”.

1. In _______ information is recorded magnetically on platters.
a) magnetic disks
b) electrical disks
c) assemblies
d) cylinders

Answer: a
Clarification: None.

2. The heads of the magnetic disk are attached to a _____ that moves all the heads as a unit.
a) spindle
b) disk arm
c) track
d) none of the mentioned

Answer: b
Clarification: None.

3. The set of tracks that are at one arm position make up a ___________
a) magnetic disks
b) electrical disks
c) assemblies
d) cylinders

Answer: d
Clarification: None.

4. The time taken to move the disk arm to the desired cylinder is called the ____________
a) positioning time
b) random access time
c) seek time
d) rotational latency

Answer: c
Clarification: None.

5. The time taken for the desired sector to rotate to the disk head is called ____________
a) positioning time
b) random access time
c) seek time
d) rotational latency

Answer: d
Clarification: None.

6. When the head damages the magnetic surface, it is known as _________
a) disk crash
b) head crash
c) magnetic damage
d) all of the mentioned

Answer: b
Clarification: None.

7. A floppy disk is designed to rotate ___________ as compared to a hard disk drive.
a) faster
b) slower
c) at the same speed
d) none of the mentioned

Answer: b
Clarification: None.

8. What is the host controller?
a) controller built at the end of each disk
b) controller at the computer end of the bus
c) all of the mentioned
d) none of the mentioned

Answer: b
Clarification: None.

9. ______ controller sends the command placed into it, via messages to the _____ controller.
a) host, host
b) disk, disk
c) host, disk
d) disk, host

Answer: c
Clarification: None.

10. What is the disk bandwidth?
a) the total number of bytes transferred
b) total time between the first request for service and the completion on the last transfer
c) the total number of bytes transferred divided by the total time between the first request for service and the completion on the last transfer
d) none of the mentioned

Answer: c

Operating System Multiple Choice Questions on “Distributed File System”.

1. What are the different ways in which clients and servers are dispersed across machines?
a) Servers may not run on dedicated machines
b) Servers and clients can be on same machines
c) Distribution cannot be interposed between a OS and the file system
d) OS cannot be distributed with the file system a part of that distribution

Answer: b

2. What are not the characteristics of a DFS?
a) login transparency and access transparency
b) Files need not contain information about their physical location
c) No Multiplicity of users
d) No Multiplicity if files

Answer: c

3. What are characteristic of a DFS?
a) Fault tolerance
b) Scalability
c) Heterogeneity of the system
d) Upgradation

Answer: d

4. What are the different ways file accesses take place?
a) sequential access
b) direct access
c) indexed sequential access
d) all of the mentioned

Answer: d

5. Which is not a major component of a file system?
a) Directory service
b) Authorization service
c) Shadow service
d) System service

Answer: c
Clarification: None.

6. What are the different ways mounting of the file system?
a) boot mounting
b) auto mounting
c) explicit mounting
d) all of the mentioned

Answer: d
Clarification: None.

7. What is the advantage of caching in remote file access?
a) Reduced network traffic by retaining recently accessed disk blocks
b) Faster network access
c) Copies of data creates backup automatically
d) None of the mentioned

Answer: a
Clarification: None.

8. What is networked virtual memory?
a) Caching
b) Segmentation
c) RAM disk
d) None of the mentioned

Answer: a
Clarification: None.

9. What are the examples of state information?
a) opened files and their clients
b) file descriptors and file handles
c) current file position pointers
d) all of the mentioned

Answer: d
Clarification: None.

10. Which is not an example of state information?
a) Mounting information
b) Description of HDD space
c) Session keys
d) Lock status

Answer: b