set-12

601. Recognition of basic syntactic constructs through reductions, this task is performed by:

1. Lexical Analysis

2. Semantic Analysis

3. Syntax Analysis

4. Structure Analysis

Show me the answer

Answer: 3. Syntax Analysis

Explanation:

• Syntax Analysis: Syntax analysis recognizes the syntactic structure of source code by reducing it to basic constructs.

• Conclusion: Syntax analysis performs this task.

602. A grammar for a programming language is a formal description of:

1. Syntax

2. Structure

3. Semantics

4. Code

Show me the answer

Answer: 1. Syntax

Explanation:

• Grammar: A grammar defines the syntax of a programming language, specifying how valid programs are structured.

• Conclusion: Grammar describes the syntax of a language.

603. ______ is a technique of temporarily removing inactive programs from the memory of a computer system:

1. Swapping

2. Semaphore

3. Spooling

4. Scheduler

Show me the answer

Answer: 1. Swapping

Explanation:

• Swapping: Swapping involves moving inactive processes out of memory to secondary storage to free up memory for active processes.

• Conclusion: Swapping temporarily removes inactive programs from memory.

604. ______ is a technique of improving the priority of processes waiting in the queue for CPU allocation:

1. Starvation

2. Revocation

3. Aging

4. Relocation

Show me the answer

Answer: 3. Aging

Explanation:

• Aging: Aging gradually increases the priority of long-waiting processes to prevent starvation.

• Conclusion: Aging improves the priority of waiting processes.

605. ______ is the time required by a sector to reach below the read/write head:

1. Seek Time

2. Access Time

3. Latency Time

4. None

Show me the answer

Answer: 3. Latency Time

Explanation:

• Latency Time: Latency time is the time required for the desired sector to rotate under the read/write head.

• Conclusion: Latency time is the time for a sector to reach the read/write head.

606. Which of the following is the most general phase-structured grammar?

1. Context-Sensitive

2. Context-Free

3. Regular

4. None of the above

Show me the answer

Answer: 1. Context-Sensitive

Explanation:

• Context-Sensitive Grammar: Context-sensitive grammar is the most general phase-structured grammar, allowing rules that depend on the context of symbols.

• Conclusion: Context-sensitive grammar is the most general.

607. File record length:

1. Should always be fixed

2. Should always be variable

3. Depends upon the size of the file

4. Should be chosen to match the data characteristics

Show me the answer

Answer: 4. Should be chosen to match the data characteristics

Explanation:

• File Record Length: The length of file records should be chosen based on the characteristics of the data being stored.

• Conclusion: File record length should match data characteristics.

608. The process is:

1. An instance of a program in execution

2. A program only

3. Processor state

4. None of the above

Show me the answer

Answer: 1. An instance of a program in execution

Explanation:

• Process: A process is an instance of a program in execution, including the program code, data, and resources.

• Conclusion: A process is an executing instance of a program.

609. A program is passive while a process is:

1. Inactive

2. Spontaneous

3. Active

4. None of the above

Show me the answer

Answer: 3. Active

Explanation:

• Program vs. Process: A program is a passive entity stored on disk, while a process is an active entity that executes the program.

• Conclusion: A process is active, while a program is passive.

610. A process is created and is initially put in the:

1. Ready queue

2. Device output

3. Any of the above

4. None of the above

Show me the answer

Answer: 1. Ready queue

Explanation:

• Process Creation: When a process is created, it is placed in the ready queue, waiting to be scheduled for execution.

• Conclusion: A new process is placed in the ready queue.

611. Exit() system call results in:

1. Forced termination

2. Normal termination

3. Abnormal termination

4. None of the above

Show me the answer

Answer: 2. Normal termination

Explanation:

• Exit() System Call: The exit() system call terminates a process normally, releasing its resources.

• Conclusion: Exit() results in normal termination.

612. A thread is a:

1. Task

2. Process

3. Program

4. Lightweight process

Show me the answer

Answer: 4. Lightweight process

Explanation:

• Thread: A thread is a lightweight process that shares memory and resources with other threads in the same process.

• Conclusion: A thread is a lightweight process.

613. Generally, we have user-level threads and:

1. Programmer-level thread

2. Kernel-level thread

3. Program-level thread

4. None of the above

Show me the answer

Answer: 2. Kernel-level thread

Explanation:

• Thread Types: Threads can be user-level (managed by the application) or kernel-level (managed by the operating system).

• Conclusion: Kernel-level threads complement user-level threads.

614. IPCs can be done through:

1. Mails

2. Messages

3. System calls

4. Traps

Show me the answer

Answer: 2. Messages

Explanation:

• IPC Mechanisms: Inter-process communication (IPC) can be done through messages, shared memory, pipes, and other mechanisms.

• Conclusion: Messages are a common IPC mechanism.

615. RR scheduling is a preemptive version of:

1. FIFO

2. SJF

3. MLQ

4. None of the above

Show me the answer

Answer: 1. FIFO

Explanation:

• Round Robin (RR): RR scheduling is a preemptive version of FIFO, where each process is given a fixed time slice.

• Conclusion: RR is a preemptive version of FIFO.

616. A scheduling where in the jobs are allowed to move between the queues:

1. Multilevel queue scheduling

2. Multilevel feedback scheduling

3. RR scheduling

4. None of the above

Show me the answer

Answer: 2. Multilevel feedback scheduling

Explanation:

• Multilevel Feedback Scheduling: This scheduling algorithm allows processes to move between queues based on their behavior and priority.

• Conclusion: Multilevel feedback scheduling allows job movement between queues.

617. In RR Scheduling, a ready queue is treated as:

1. Circular queue

2. Doubly linked list

3. Stack

4. None of the above

Show me the answer

Answer: 1. Circular queue

Explanation:

• Round Robin (RR): In RR scheduling, the ready queue is treated as a circular queue, where processes are given time slices in a cyclic manner.

• Conclusion: The ready queue in RR is a circular queue.

618. FIFO scheduling is:

1. Preemptive

2. Non-preemptive

3. Deadline scheduling

4. None of the above

Show me the answer

Answer: 2. Non-preemptive

Explanation:

• FIFO Scheduling: FIFO (First-In-First-Out) scheduling is non-preemptive, meaning a process runs to completion once it starts.

• Conclusion: FIFO is non-preemptive.

619. The indefinite blocking of low-priority processes by high-priority processes is known as:

1. Starvation

2. Deadlock

3. Aging

4. None of the above

Show me the answer

Answer: 1. Starvation

Explanation:

• Starvation: Starvation occurs when low-priority processes are indefinitely blocked by high-priority processes.

• Conclusion: Starvation describes indefinite blocking of low-priority processes.

620. The technique of gradually increasing the priority of processes that wait in the system for a long time is called:

1. Aging

2. Throughput

3. FCFS

4. None of the above

Show me the answer

Answer: 1. Aging

Explanation:

• Aging: Aging increases the priority of long-waiting processes to prevent starvation.

• Conclusion: Aging gradually increases the priority of waiting processes.

621. The main objective of scheduling is:

1. CPU utilization

2. Increase the throughput

3. Both A and B

4. None of the above

Show me the answer

Answer: 3. Both A and B

Explanation:

• Scheduling Objectives: The main objectives of scheduling are to maximize CPU utilization and throughput.

• Conclusion: Scheduling aims to improve CPU utilization and throughput.

622. The total time elapsed from the time the job is submitted (or process is created) to the time the job (or process) is completed is called:

1. Response time

2. Waiting time

3. Turnaround time

4. None of the above

Show me the answer

Answer: 3. Turnaround time

Explanation:

• Turnaround Time: Turnaround time is the total time from job submission to completion.

• Conclusion: Turnaround time measures the total time for job completion.

623. ______ is defined as the average fraction of time during which the CPU is busy, executing either user programs or system modules:

1. Throughput

2. CPU utilization

3. Response time

4. Waiting time

Show me the answer

Answer: 2. CPU utilization

Explanation:

• CPU Utilization: CPU utilization measures the fraction of time the CPU is busy executing tasks.

• Conclusion: CPU utilization measures the busy time of the CPU.

624. In ______ scheduling, if once a process has been allocated CPU, then the CPU cannot be taken away from that process:

1. Pre-emptive scheduling

2. Non-preemptive scheduling

3. Both A and C

4. None of the above

Show me the answer

Answer: 2. Non-preemptive scheduling

Explanation:

• Non-Preemptive Scheduling: In non-preemptive scheduling, once a process starts execution, it cannot be interrupted until it completes.

• Conclusion: Non-preemptive scheduling does not allow CPU reallocation.

625. In ______, the CPU can be taken away before the completion of the process:

1. Pre-emptive scheduling

2. Non-preemptive

3. Both A and B

4. None of the above

Show me the answer

Answer: 1. Pre-emptive scheduling

Explanation:

• Pre-emptive Scheduling: In pre-emptive scheduling, the CPU can be taken away from a process before it completes.

• Conclusion: Pre-emptive scheduling allows CPU reallocation.

626. “If there are n-processes in a ready queue and the time quantum is ‘q’ time intervals, then each process gets ‘1/n’, of the CPU time in the chunks of at most ‘q’ units of time. Each process will have to wait for (n -1) x q time unit until its next time quantum comes in” This principle is suitable for which one of the following:

1. Round robin algorithm

2. SFJ

3. FCFS

4. None of the above

Show me the answer

Answer: 1. Round robin algorithm

Explanation:

• Round Robin (RR): RR scheduling allocates CPU time in fixed time slices (quantum) to each process in the ready queue.

• Conclusion: This principle describes the Round Robin algorithm.

627. Process can be in one of the following states:

1. New, Ready

2. Running

3. Waiting, Blocked, Terminate

4. All of the above

Show me the answer

Answer: 4. All of the above

Explanation:

• Process States: A process can be in states such as New, Ready, Running, Waiting, Blocked, or Terminated.

• Conclusion: All of the above are valid process states.

628. Process is:

1. Loosely coupled

2. Tightly coupled

3. Both A and B

4. None of the above

Show me the answer

Answer: 1. Loosely coupled

Explanation:

• Process Coupling: Processes are loosely coupled, meaning they operate independently and communicate through inter-process communication mechanisms.

• Conclusion: Processes are loosely coupled.

629. Process is:

1. Lightweight process

2. Heavyweight process

3. Tightly coupled

4. None of the above

Show me the answer

Answer: 2. Heavyweight process

Explanation:

• Process vs. Thread: A process is a heavyweight entity with its own memory space, while a thread is a lightweight entity that shares memory with other threads.

• Conclusion: A process is a heavyweight entity.

630. The high paging activity is called:

1. Segmentation

2. Thrashing

3. Demand Paging

4. None of the above

Show me the answer

Answer: 2. Thrashing

Explanation:

• Thrashing: Thrashing occurs when the system spends more time swapping pages in and out of memory than executing processes.

• Conclusion: High paging activity is called thrashing.

631. The process of merging adjacent holes to form a single larger hole is called as:

1. Fragmentation

2. Coalescing

3. Swapping

4. None of the above

Show me the answer

Answer: 2. Coalescing

Explanation:

• Coalescing: Coalescing is the process of merging adjacent free memory blocks to form a larger contiguous block.

• Conclusion: Coalescing merges adjacent holes.

632. The degree of multiprogramming is controlled by:

1. CPU scheduler

2. Context switching

3. Long-term scheduler

4. Medium-term scheduler

Show me the answer

Answer: 3. Long-term scheduler

Explanation:

• Long-Term Scheduler: The long-term scheduler controls the degree of multiprogramming by deciding which jobs are admitted to the system.

• Conclusion: The long-term scheduler controls multiprogramming.

633. Thrashing occurs:

1. When excessive swapping takes place

2. When you thrash your computer

3. Whenever deadlock occurs

4. When no swapping takes place

Show me the answer

Answer: 1. When excessive swapping takes place

Explanation:

• Thrashing: Thrashing occurs when the system spends more time swapping pages than executing processes, leading to poor performance.

• Conclusion: Thrashing is caused by excessive swapping.

634. Boundary registers:

1. Are available in temporary program variables storage

2. Are only necessary with fixed partitions

3. Track the beginning and ending of programs

4. Track page boundaries

Show me the answer

Answer: 3. Track the beginning and ending of programs

Explanation:

• Boundary Registers: Boundary registers track the start and end addresses of programs in memory.

• Conclusion: Boundary registers track program boundaries.

635. A scheduling algorithm is fair:

1. If no process faces starvation

2. If a process is starved, detect it and run it with high priority

3. If it uses semaphores

4. Only if a queue is used for scheduling

Show me the answer

Answer: 1. If no process faces starvation

Explanation:

• Fair Scheduling: A fair scheduling algorithm ensures that no process is starved of CPU time.

• Conclusion: Fairness in scheduling prevents starvation.

636. A critical region:

1. Is a piece of code which only one process executes at a time

2. Is a region prone to deadlock

3. Is a piece of code which only a finite number of processes executes

4. Is found only in Windows N operating system

Show me the answer

Answer: 1. Is a piece of code which only one process executes at a time

Explanation:

• Critical Region: A critical region is a segment of code where shared resources are accessed, and only one process can execute it at a time to prevent race conditions.

• Conclusion: A critical region is executed by only one process at a time.

637. In one of the deadlock prevention methods, impose a total ordering of all resource types, and require that each process requests resources in an increasing order of enumeration. This violates the ______ condition of deadlock:

1. Mutual exclusion

2. Hold and Wait

3. Circular wait

4. No preemption

Show me the answer

Answer: 3. Circular wait

Explanation:

• Circular Wait: Imposing a total ordering of resources prevents circular wait, as processes cannot request resources in a cyclic manner.

• Conclusion: This method violates the circular wait condition.

638. Semaphore can be used for solving:

1. Wait and signal

2. Deadlock

3. Synchronization

4. Priority

Show me the answer

Answer: 3. Synchronization

Explanation:

• Semaphore: Semaphores are used for process synchronization, ensuring that processes access shared resources in a controlled manner.

• Conclusion: Semaphores solve synchronization problems.

639. The hardware mechanism that enables a device to notify the CPU is called:

1. Polling

2. Interrupt

3. System call

4. None of the above

Show me the answer

Answer: 2. Interrupt

Explanation:

• Interrupt: An interrupt is a hardware mechanism that allows a device to notify the CPU of an event requiring attention.

• Conclusion: Interrupts enable devices to notify the CPU.

640. ______ begins at the root and follows a path down to the specified file:

1. Relative path name

2. Absolute path name

3. Standalone name

4. All of the above

Show me the answer

Answer: 2. Absolute path name

Explanation:

• Absolute Path Name: An absolute path name starts at the root directory and specifies the complete path to a file.

• Conclusion: Absolute path names begin at the root.

641. Process state is a part of:

1. Process control block

2. Node

3. File allocation table

4. None of the above

Show me the answer

Answer: 1. Process control block

Explanation:

• Process Control Block (PCB): The PCB contains information about a process, including its state.

• Conclusion: Process state is part of the PCB.

642. Virtual memory is commonly implemented by:

1. Segmentation

2. Swapping

3. Demand paging

4. None of the above

Show me the answer

Answer: 3. Demand paging

Explanation:

• Demand Paging: Virtual memory is commonly implemented using demand paging, where pages are loaded into memory only when needed.

• Conclusion: Demand paging is the most common implementation of virtual memory.

643. Paging:

1. Solves the memory fragmentation problem

2. Allows modular programming

3. Allows structured programming

4. Avoids deadlock

Show me the answer

Answer: 1. Solves the memory fragmentation problem

Explanation:

• Paging: Paging divides memory into fixed-size pages, reducing external fragmentation.

• Conclusion: Paging solves the memory fragmentation problem.

644. Which of the following is a criterion to evaluate a scheduling algorithm?

1. CPU Utilization: keep CPU utilization as high as possible

2. Throughput: number of processes completed per unit time

3. Waiting time: amount of time spent ready to run but not running

4. All of the above

Show me the answer

Answer: 4. All of the above

Explanation:

• Scheduling Criteria: CPU utilization, throughput, and waiting time are key criteria for evaluating scheduling algorithms.

• Conclusion: All of the above are valid criteria.

645. Which of the following is contained in Process Control Block (PCB)?

1. Process number

2. List of open files

3. Memory limits

4. All of the above

Show me the answer

Answer: 4. All of the above

Explanation:

• PCB Contents: The PCB contains information such as the process number, list of open files, and memory limits.

• Conclusion: All of the above are contained in the PCB.

646. With the round-robin CPU scheduling in a time-shared system:

1. Using very large time slice degenerates into the first-come-first-served algorithm

2. Using extremely small time slices improves performance

3. Using extremely small time slices degenerates into the last-in-first-out algorithm

4. Using medium-sized time slices leads to the shortest request time first algorithm

Show me the answer

Answer: 1. Using very large time slice degenerates into the first-come-first-served algorithm

Explanation:

• Round Robin (RR): In RR scheduling, if the time slice is very large, it behaves like FCFS, as each process runs to completion within its time slice.

• Conclusion: A very large time slice makes RR similar to FCFS.