Category: Operating System Objective Questions

Operating System Multiple Choice Questions & Answers on “Virtual Memory – Allocation of Frames”.

1. The minimum number of frames to be allocated to a process is decided by the ____________
a) the amount of available physical memory
b) operating System
c) instruction set architecture
d) none of the mentioned

Answer: c
Clarification: None.

2. When a page fault occurs before an executing instruction is complete if ____________
a) the instruction must be restarted
b) the instruction must be ignored
c) the instruction must be completed ignoring the page fault
d) none of the mentioned

Answer: a
Clarification: None.

3. Consider a machine in which all memory reference instructions have only one memory address, for them we need at least _____ frame(s).
a) one
b) two
c) three
d) none of the mentioned

Answer: b
Clarification: At least one frame for the instruction and one for the memory reference.

4. The maximum number of frames per process is defined by ____________
a) the amount of available physical memory
b) operating System
c) instruction set architecture
d) none of the mentioned

Answer: a
Clarification: None.

5. The algorithm in which we split m frames among n processes, to give everyone an equal share, m/n frames is known as ____________
a) proportional allocation algorithm
b) equal allocation algorithm
c) split allocation algorithm
d) none of the mentioned

Answer: b
Clarification: None.

6. The algorithm in which we allocate memory to each process according to its size is known as ____________
a) proportional allocation algorithm
b) equal allocation algorithm
c) split allocation algorithm
d) none of the mentioned

Answer: a
Clarification: None.

7. With either equal or proportional algorithm, a high priority process is treated ___________ a low priority process.
a) greater than
b) same as
c) lesser than
d) none of the mentioned

Answer: b
Clarification: None.

8. _________ replacement allows a process to select a replacement frame from the set of all frames, even if the frame is currently allocated to some other process.
a) Local
b) Universal
c) Global
d) Public

Answer: c
Clarification: None.

9. _________ replacement allows each process to only select from its own set of allocated frames.
a) Local
b) Universal
c) Global
d) Public

Answer: a
Clarification: None.

10. One problem with the global replacement algorithm is that ____________
a) it is very expensive
b) many frames can be allocated to a process
c) only a few frames can be allocated to a process
d) a process cannot control its own page – fault rate

Answer: d
Clarification: None.

11. ________ replacement generally results in greater system throughput.
a) Local
b) Global
c) Universal
d) Public

Answer: b

Operating System Question Bank on “File System Implementation – Network File System”.

1. The NFS servers ____________
a) are stateless
b) save the current state of the request
c) maybe stateless
d) none of the mentioned

Answer: a

2. Every NFS request has a _________ allowing the server to determine if a request is duplicated or if any are missing.
a) name
b) transaction
c) sequence number
d) all of the mentioned

Answer: c

3. A server crash and recovery will __________ to a client.
a) be visible
b) affect
c) be invisible
d) harm

Answer: c
Clarification: All blocks that the server is managing for the client will be intact.

4. The server must write all NFS data ___________
a) synchronously
b) asynchronously
c) index-wise
d) none of the mentioned

Answer: a
Clarification: None.

5. A single NFS write procedure ____________
a) can be atomic
b) is atomic
c) is non atomic
d) none of the mentioned

Answer: b
Clarification: None.

6. The NFS protocol __________ concurrency control mechanisms.
a) provides
b) does not provide
c) may provide
d) none of the mentioned

Answer: b
Clarification: None.

7. _______________ in NFS involves the parsing of a path name into separate directory entries – or components.
a) Path parse
b) Path name parse
c) Path name translation
d) Path name parsing

Answer: c
Clarification: None.

8. For every pair of component and directory vnode after path name translation ____________
a) a single NFS lookup call is used sequentially
b) a single NFS lookup call is used beginning from the last component
c) at least two NFS lookup calls per component are performed
d) a separate NFS lookup call is performed

Answer: d
Clarification: None.

9. When a client has a cascading mount _______ server(s) is/are involved in a path name traversal.
a) at least one
b) more than one
c) more than two
d) more than three

Answer: b

Operating System Multiple Choice Questions on “Distributed Operating System – Network Structure & Topology”.

1. What are the parts of network structure?
a) Workstation
b) Gateway
c) Laptop
d) All of the mentioned

Answer: d

2. What is a valid network topology?
a) Multiaccess bus
b) Ring
c) Star
d) All of the mentioned

Answer: d

3. What are sites in network topology compared?
a) Basic cost
b) Communication cost
c) Reliability
d) All of the mentioned

Answer: d

4. Which design features of a communication network are important?
a) Naming and name resolution
b) Routing strategies
c) Connection strategies
d) All of the mentioned

Answer: d

5. What are the characteristics of Naming and Name resolution?
a) name systems in the network
b) address messages with the process-id
c) virtual circuit
d) message switching

Answer: b
Clarification: None.

6. What are routing strategies which is not used in distributed systems?
a) Fixed routing
b) Token routing
c) Virtual circuit
d) Dynamic routing

Answer: c
Clarification: None.

7. What are the connection strategies not used in distributed systems?
a) Circuit switching
b) Message switching
c) Token switching
d) Packet switching

Answer: c
Clarification: None.

8. How is are collisions avoided in network?
a) Carrier sense with multiple access (CSMA); collision detection (CD)
b) Carrier sense multiple access with collision avoidance
c) Message slots
d) All of the mentioned

Answer: d
Clarification: None.

9. What is a common problem found in distributed system?
a) Process Synchronization
b) Communication synchronization
c) Deadlock problem
d) Power failure

Answer: c
Clarification: None.

Operating System Multiple Choice Questions on “Processes”.

1. The systems which allow only one process execution at a time, are called __________
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none of the mentioned

Answer: b
Clarification: Those systems which allows more than one process execution at a time, are called multiprogramming systems. Uniprocessing means only one processor.

2. In operating system, each process has its own __________
a) address space and global variables
b) open files
c) pending alarms, signals and signal handlers
d) all of the mentioned

Answer: d
Clarification: In Operating Systems, each process has its own address space which contains code, data, stack and heap segments or sections. Each process also has a list of files which is opened by the process as well as all pending alarms, signals and various signal handlers.

3. In Unix, Which system call creates the new process?
a) fork
b) create
c) new
d) none of the mentioned

Answer: a
Clarification: In UNIX, a new process is created by fork() system call. fork() system call returns a process ID which is generally the process id of the child process created.

4. A process can be terminated due to __________
a) normal exit
b) fatal error
c) killed by another process
d) all of the mentioned

Answer: d
Clarification: A process can be terminated normally by completing its task or because of fatal error or killed by another process or forcefully killed by a user. When the process completes its task without any error then it exits normally. The process may exit abnormally because of the occurrence of fatal error while it is running. The process can be killed or terminated forcefully by another process.

5. What is the ready state of a process?
a) when process is scheduled to run after some execution
b) when process is unable to run until some task has been completed
c) when process is using the CPU
d) none of the mentioned

Answer: a
Clarification: Ready state of the process means process has all necessary resources which are required for execution of that process when CPU is allocated. Process is ready for execution but waiting for the CPU to be allocated.

6. What is interprocess communication?
a) communication within the process
b) communication between two process
c) communication between two threads of same process
d) none of the mentioned

Answer: b
Clarification: Interprocess Communication (IPC) is a communication mechanism that allows processes to communicate with each other and synchronise their actions without using the same address space. IPC can be achieved using shared memory and message passing.

7. A set of processes is deadlock if __________
a) each process is blocked and will remain so forever
b) each process is terminated
c) all processes are trying to kill each other
d) none of the mentioned

Answer: a
Clarification: Deadlock is a situation which occurs because process A is waiting for one resource and holds another resource (blocking resource). At the same time another process B demands blocking a resource as it is already held by a process A, process B is waiting state unless and until process A releases occupied resource.

8. A process stack does not contain __________
a) Function parameters
b) Local variables
c) Return addresses
d) PID of child process

Answer: d
Clarification: Process stack contains Function parameters, Local variables and Return address. It does not contain the PID of child process.

9. Which system call can be used by a parent process to determine the termination of child process?
a) wait
b) exit
c) fork
d) get

Answer: a
Clarification: wait() system call is used by the parent process to determine termination of child process. The parent process uses wait() system call and gets the exit status of the child process as well as the pid of the child process which is terminated.

10. The address of the next instruction to be executed by the current process is provided by the __________
a) CPU registers
b) Program counter
c) Process stack
d) Pipe

Answer: b
Clarification: The address of the next instruction to be executed by the current process is provided by the Program Counter. After every instruction is executed, the Program Counter is incremented by 1 i.e. address of the next instruction to be executed. CPU fetches instruction from the address denoted by Program Counter and execute it.

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