> For the complete documentation index, see [llms.txt](https://nec-license.gitbook.io/books/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nec-license.gitbook.io/books/7.-data-structures-and-algorithm-database-system-and-operating-system/mcqs/mcqs-on-operating-system/set-10.md).
# set-10
#### 451. The function(s) of the file system is (are):
1. To provide complete file naming freedom to the users and to permit controlled sharing of files
2. To provide for long and short-term storage of files with appropriate economic tradeoffs
3. To provide security against loss of information due to system failure
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **File System Functions:** The file system provides file naming, storage management, security, and controlled sharing of files. It also ensures data integrity and recovery in case of system failures.
* **Conclusion:** All the listed functions are responsibilities of the file system.
#### 452. Moving a process from main memory to disk is called:
1. Scheduling
2. Swapping
3. Caching
4. Spooling
Show me the answer
**Answer:** 2. Swapping
**Explanation:**
* **Swapping:** Swapping is the process of moving a process from main memory to disk (secondary storage) to free up memory for other processes.
* **Conclusion:** Swapping is used to manage memory in multiprogramming systems.
#### 453. In order to allow only one process to enter its critical section, binary semaphores are initialized to:
1. 0
2. 1
3. 2
4. 3
Show me the answer
**Answer:** 2. 1
**Explanation:**
* **Binary Semaphore:** A binary semaphore is initialized to 1 to allow only one process to enter the critical section at a time. The semaphore is decremented to 0 when a process enters the critical section and incremented back to 1 when the process exits.
* **Conclusion:** Binary semaphores are initialized to 1 for mutual exclusion.
#### 454. The state transition initiated by the user process itself in an operating system is:
1. Block
2. Wake up
3. Dispatch
4. Timer run out
Show me the answer
**Answer:** 1. Block
**Explanation:**
* **State Transition:** A process can transition to the Blocked state when it requests an I/O operation or waits for an event. This transition is initiated by the process itself.
* **Conclusion:** The Block state transition is user-initiated.
#### 455. Which of the following terms refers to the degree to which data in a database system are accurate and correct?
1. Data security
2. Data independence
3. Data validity
4. Data integrity
Show me the answer
**Answer:** 4. Data integrity
**Explanation:**
* **Data Integrity:** Data integrity refers to the accuracy, consistency, and correctness of data in a database system. It ensures that data remains reliable and valid over its lifecycle.
* **Conclusion:** Data integrity ensures the accuracy and correctness of data.
#### 456. The total time to prepare a disk drive mechanism for a block of data to be read from it is:
1. Latency
2. Latency plus transmission time
3. Latency plus seek time
4. Latency plus seek time plus transmission time
Show me the answer
**Answer:** 3. Latency plus seek time
**Explanation:**
* **Disk Access Time:** The total time to prepare a disk drive for reading a block of data includes:
* **Seek Time:** Time to move the disk arm to the correct track.
* **Latency:** Time for the disk to rotate to the correct sector.
* **Conclusion:** The total preparation time is the sum of seek time and latency.
#### 457. The paging rate:
1. Should never be greater than 100 per second
2. Is greater for large programs
3. Is the number of I/O interrupts each second
4. Increases as the number of page faults increases
Show me the answer
**Answer:** 4. Increases as the number of page faults increases
**Explanation:**
* **Paging Rate:** The paging rate is the rate at which pages are swapped in and out of memory. It increases as the number of page faults increases, indicating higher memory contention.
* **Conclusion:** The paging rate is directly related to the number of page faults.
#### 458. Thrashing:
1. Is a natural consequence of virtual memory systems
2. Can always be avoided by swapping
3. Always occurs on large computers
4. Can be caused by poor paging algorithms
Show me the answer
**Answer:** 4. Can be caused by poor paging algorithms
**Explanation:**
* **Thrashing:** Thrashing occurs when the system spends more time swapping pages in and out of memory than executing processes. It is often caused by poor paging algorithms or insufficient memory.
* **Conclusion:** Thrashing can be caused by inefficient paging algorithms.
#### 459. The computational technique used to compute the disk storage address of individual records is called:
1. Bubble memory
2. Dynamic reallocation
3. Key fielding
4. Hashing
Show me the answer
**Answer:** 4. Hashing
**Explanation:**
* **Hashing:** Hashing is a technique used to compute the disk storage address of individual records by applying a hash function to the record's key. It allows for efficient data retrieval.
* **Conclusion:** Hashing is used to compute disk storage addresses.
#### 460. Capacity planning:
1. Requires detailed system performance information
2. Is independent of the operating system
3. Does not depend on the monitoring tools available
4. Is not needed in small installations
Show me the answer
**Answer:** 1. Requires detailed system performance information
**Explanation:**
* **Capacity Planning:** Capacity planning involves analyzing system performance data to ensure that the system can handle future workloads. It requires detailed performance metrics and monitoring tools.
* **Conclusion:** Capacity planning relies on detailed system performance information.
#### 461. In a multiprogramming system, a set of processes is deadlocked if each process in the set is waiting for an event to occur that can be initiated only by another process in the set. Which of the following is not one of the four conditions that are necessary for deadlock to occur?
1. Non-preemption
2. Partial assignment of resources
3. Process suspension
4. Circular wait
Show me the answer
**Answer:** 3. Process suspension
**Explanation:**
* **Deadlock Conditions:** The four necessary conditions for deadlock are:
1. Mutual Exclusion
2. Hold and Wait
3. No Preemption
4. Circular Wait
* **Conclusion:** Process suspension is not a condition for deadlock.
#### 462. Belady's anomaly occurs in:
1. Optimal replacement
2. LRU
3. FIFO
4. Both in FIFO and LRU
Show me the answer
**Answer:** 3. FIFO
**Explanation:**
* **Belady's Anomaly:** Belady's anomaly occurs in the FIFO page replacement algorithm, where increasing the number of page frames can lead to an increase in the number of page faults.
* **Conclusion:** FIFO is the algorithm that suffers from Belady's anomaly.
#### 463. The CPU, after receiving an interrupt from an I/O device:
1. Halts for a predetermined time
2. Hands over control of the address bus and data bus to the interrupting device
3. Branches off to the interrupt service routine immediately
4. Branches off to the interrupt service routine after completion of the current instruction
Show me the answer
**Answer:** 4. Branches off to the interrupt service routine after completion of the current instruction
**Explanation:**
* **Interrupt Handling:** When the CPU receives an interrupt, it completes the current instruction before branching to the interrupt service routine (ISR) to handle the interrupt.
* **Conclusion:** The CPU processes interrupts after completing the current instruction.
#### 464. Which of the following is not a characteristic of a daisy chaining priority control scheme?
1. Priority is programmable
2. It is relatively easy to add more devices to the chain
3. The failure of one device may affect other devices on the chain
4. The number of control lines is independent of the number of devices on the chain
Show me the answer
**Answer:** 1. Priority is programmable
**Explanation:**
* **Daisy Chaining:** In a daisy chaining priority control scheme, the priority of devices is fixed by their physical position in the chain. It is not programmable.
* **Conclusion:** Priority is not programmable in daisy chaining.
#### 465. An example of a system development program is:
1. Operating system
2. Database management systems
3. Performance monitors
4. Language translators
Show me the answer
**Answer:** 4. Language translators
**Explanation:**
* **System Development Programs:** Language translators, such as compilers and assemblers, are examples of system development programs used to convert high-level code into machine code.
* **Conclusion:** Language translators are system development programs.
#### 466. Which of the following is not a part of the operating system?
1. Supervisor
2. Job-control program
3. Performance monitor
4. Input/output control program
Show me the answer
**Answer:** 3. Performance monitor
**Explanation:**
* **Operating System Components:** The supervisor, job-control program, and I/O control program are core components of the operating system. Performance monitors are typically external tools.
* **Conclusion:** Performance monitors are not part of the operating system.
#### 467. If special forms are needed for printing the output, the programmer specifies these through:
1. JCL
2. Utility programs
3. IPL
4. Load modules
Show me the answer
**Answer:** 1. JCL
**Explanation:**
* **Job Control Language (JCL):** JCL is used to specify special forms, printer configurations, and other job-related parameters in batch processing systems.
* **Conclusion:** Special forms are specified using JCL.
#### 468. Which of the following is not an advantage of multiprogramming?
1. Increased throughput
2. Shorter response time
3. Decreased operating system overhead
4. Ability to assign priorities to jobs
Show me the answer
**Answer:** 3. Decreased operating system overhead
**Explanation:**
* **Multiprogramming Advantages:** Multiprogramming increases throughput, reduces response time, and allows priority-based scheduling. However, it increases operating system overhead due to process management.
* **Conclusion:** Multiprogramming does not decrease operating system overhead.
#### 469. The problem of thrashing is affected significantly by:
1. Program structure
2. Primary-storage size
3. Program size
4. None of the above
Show me the answer
**Answer:** 1. Program structure
**Explanation:**
* **Thrashing:** Thrashing is influenced by the program's memory access patterns (program structure). Poor locality of reference can lead to excessive page faults and thrashing.
* **Conclusion:** Program structure significantly affects thrashing.
#### 470. Logical extension of multiprogramming of operating system is:
1. Time sharing
2. Single programming
3. Multi-tasking
4. Both (A) and (B)
Show me the answer
**Answer:** 4. Both (A) and (B)
**Explanation:**
* **Multiprogramming Extension:** Time sharing and multi-tasking are logical extensions of multiprogramming, allowing multiple processes to share CPU time and resources.
* **Conclusion:** Both time sharing and multi-tasking extend multiprogramming.
#### 471. Under multiprogramming, turnaround time for short jobs is usually...... and that for long jobs is slightly......
1. Lengthened; shortened
2. Shortened; shortened
3. Shortened; lengthened
4. Shortened; unchanged
Show me the answer
**Answer:** 3. Shortened; lengthened
**Explanation:**
* **Turnaround Time:** In multiprogramming, short jobs are executed quickly, reducing their turnaround time. Long jobs may experience slightly longer turnaround times due to resource contention.
* **Conclusion:** Turnaround time for short jobs is shortened, while for long jobs, it is slightly lengthened.
#### 472. Remote computing service involves the use of time-sharing and......
1. Multiprocessing
2. Batch processing
3. Interactive processing
4. Real-time processing
Show me the answer
**Answer:** 4. Real-time processing
**Explanation:**
* **Remote Computing:** Remote computing services often use time-sharing and real-time processing to provide interactive and responsive user experiences.
* **Conclusion:** Real-time processing is used in remote computing services.
#### 473. Under which circumstances the scheduling scheme is non-preemptive:
1. When a process switches from running to waiting state, when a process terminates
2. When a process switches from waiting to the ready state
3. When a process switches from waiting to the ready state
4. Both (A) and (B)
Show me the answer
**Answer:** 1. When a process switches from running to waiting state, when a process terminates
**Explanation:**
* **Non-Preemptive Scheduling:** In non-preemptive scheduling, the CPU is not forcibly taken from a running process. The process releases the CPU voluntarily when it switches to the waiting state or terminates.
* **Conclusion:** Non-preemptive scheduling occurs when a process voluntarily releases the CPU.
#### 474. Under which circumstances the scheduling scheme is preemptive:
1. When a process switches from running to waiting state
2. When a process switches from running to the ready state
3. When a process switches from waiting to the ready state
4. Both (B) and (C)
Show me the answer
**Answer:** 4. Both (B) and (C)
**Explanation:**
* **Preemptive Scheduling:** Preemptive scheduling occurs when the CPU is forcibly taken from a running process, such as when a higher-priority process becomes ready or when a time slice expires.
* **Conclusion:** Preemptive scheduling occurs when the CPU is forcibly reallocated.
#### 475. ......gives control of the CPU to the process selected by the short-term scheduler.
1. Long-term scheduler
2. Dispatcher
3. Medium-term scheduler
4. None of the above
Show me the answer
**Answer:** 2. Dispatcher
**Explanation:**
* **Dispatcher:** The dispatcher is responsible for giving control of the CPU to the process selected by the short-term scheduler. It performs context switching and sets up the CPU registers for the new process.
* **Conclusion:** The dispatcher transfers control to the selected process.
#### 476. Which of the following are the functions of the dispatcher?
1. Swapping
2. Jumping to the proper location in the user program to restart that program
3. Scheduling
4. All of the above
Show me the answer
**Answer:** 2. Jumping to the proper location in the user program to restart that program
**Explanation:**
* **Dispatcher Functions:** The dispatcher's primary function is to load the CPU registers and jump to the proper location in the user program to restart execution.
* **Conclusion:** The dispatcher ensures the selected process resumes execution correctly.
#### 477. Which of the following are CPU scheduling criteria?
1. CPU utilization
2. Dispatcher latency
3. Waiting time
4. Both (A) and (B)
Show me the answer
**Answer:** 4. Both (A) and (B)
**Explanation:**
* **CPU Scheduling Criteria:** CPU utilization and waiting time are key criteria for evaluating CPU scheduling algorithms. Dispatcher latency is also important as it affects the responsiveness of the system.
* **Conclusion:** Both CPU utilization and dispatcher latency are scheduling criteria.
#### 478. Which of the following is true for the algorithms for allocating regions of contiguous memory?
1. First-fit
2. Best-fit
3. Next-fit
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **Memory Allocation Algorithms:** First-fit, best-fit, and next-fit are all algorithms used for allocating contiguous memory regions. They differ in how they search for and allocate memory blocks.
* **Conclusion:** All the listed algorithms are used for contiguous memory allocation.
#### 479. The first-fit algorithm for allocating regions of contiguous memory does......
1. Scan memory region list from start for first fit
2. Scan memory region list from point of last allocation to next
3. Tends to leave small unusable regions, and slower due to requirement of searching the entire list
4. There is no such algorithm
Show me the answer
**Answer:** 1. Scan memory region list from start for first fit
**Explanation:**
* **First-Fit Algorithm:** The first-fit algorithm scans the memory region list from the start and allocates the first block that is large enough to satisfy the request.
* **Conclusion:** First-fit scans from the start for the first suitable block.
#### 480. The best-fit algorithm for allocating regions of contiguous memory does......
1. Scan memory regions from start for first fit
2. Pick the closest free region in the entire list
3. There is no such algorithm
4. Find the worst fit in the entire list
Show me the answer
**Answer:** 2. Pick the closest free region in the entire list
**Explanation:**
* **Best-Fit Algorithm:** The best-fit algorithm searches the entire memory region list to find the smallest free block that is large enough to satisfy the request.
* **Conclusion:** Best-fit picks the closest free region in the entire list.
#### 481. Which of the following are scheduling algorithms:
1. First come first serve
2. Priority scheduling
3. Shortest job first
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **Scheduling Algorithms:** FCFS, priority scheduling, and SJF are all common CPU scheduling algorithms used in operating systems.
* **Conclusion:** All the listed algorithms are scheduling algorithms.
#### 482. Routine is not loaded until it is called. All routines are kept on disk in a reloadable load format. The main program is loaded into memory & is executed. This type of loading is called \_\_\_\_\_\_.
1. Static loading
2. Dynamic linking
3. Dynamic loading
4. Overlays
Show me the answer
**Answer:** 3. Dynamic loading
**Explanation:**
* **Dynamic Loading:** Dynamic loading allows routines to be loaded into memory only when they are called. This reduces memory usage by loading only the necessary parts of a program.
* **Conclusion:** Dynamic loading is used to load routines on demand.
#### 483. Which of the following is crucial time while accessing data on the disk?
1. Seek time
2. Transmission time
3. Rotational time
4. Waiting time
Show me the answer
**Answer:** 1. Seek time
**Explanation:**
* **Seek Time:** Seek time is the time taken to move the disk arm to the correct track. It is a crucial factor in disk access time.
* **Conclusion:** Seek time is the most critical factor in disk access time.
#### 484. The host repeatedly checks if the controller is busy until it is not. It is in a loop that status register’s busy bit becomes clear. This is called \_\_\_\_\_\_ and a mechanism for the hardware controller to notify the CPU that it is ready is called \_\_\_\_\_\_.
1. Interrupt and Polling
2. Polling and Interrupt
3. Polling and Spooling
4. Deadlock and Starvation
Show me the answer
**Answer:** 2. Polling and Interrupt
**Explanation:**
* **Polling:** Polling is the process of repeatedly checking the status of a device to determine if it is ready.
* **Interrupt:** An interrupt is a mechanism for the hardware controller to notify the CPU that it is ready.
* **Conclusion:** Polling and interrupt are the correct terms.
#### 485. Unix Operating System is an \_\_\_\_\_\_.
1. Time Sharing Operating System
2. Multi-tasking Operating System
3. Multi-User Operating Systems
4. All of the Above
Show me the answer
**Answer:** 4. All of the Above
**Explanation:**
* **Unix OS:** Unix is a time-sharing, multi-tasking, and multi-user operating system. It allows multiple users to run multiple tasks simultaneously.
* **Conclusion:** Unix is all of the listed types of operating systems.
#### 486. Which of the following memory allocation scheme suffers from External fragmentation?
1. Segmentation
2. Swapping
3. Pure demand paging
4. Paging
Show me the answer
**Answer:** 1. Segmentation
**Explanation:**
* **External Fragmentation:** Segmentation suffers from external fragmentation because memory is divided into variable-sized segments, leaving small, unusable gaps between segments.
* **Conclusion:** Segmentation is prone to external fragmentation.
#### 487. Information about a process is maintained in a \_\_\_\_\_\_.
1. Stack
2. Process Control Block
3. Translation Look aside Buffer
4. Program Control Block
Show me the answer
**Answer:** 2. Process Control Block
**Explanation:**
* **Process Control Block (PCB):** The PCB contains all the information about a process, including its state, program counter, registers, and memory allocation.
* **Conclusion:** The PCB maintains process information.
#### 488. Distributed OS works on the \_\_\_\_\_\_ principle.
1. File Foundation
2. Multi system image
3. Single system images
4. Networking image
Show me the answer
**Answer:** 3. Single system images
**Explanation:**
* **Distributed OS:** A distributed operating system provides a single system image, making multiple networked computers appear as a single system to users.
* **Conclusion:** Distributed OS works on the single system image principle.
#### 489. The problem of fragmentation arises in \_\_\_\_\_\_.
1. Static storage allocation
2. Stack allocation storage
3. Stack allocation with dynamic binding
4. Heap allocation
Show me the answer
**Answer:** 4. Heap allocation
**Explanation:**
* **Fragmentation:** Fragmentation occurs in heap allocation due to the dynamic allocation and deallocation of memory blocks, leading to small, unusable gaps.
* **Conclusion:** Fragmentation is a problem in heap allocation.
#### 490. Which file system does DOS typically use?
1. FAT16
2. NTFS
3. FAT32
4. WNFS
Show me the answer
**Answer:** 1. FAT16
**Explanation:**
* **DOS File System:** DOS typically uses the FAT16 file system, which supports 16-bit file allocation tables.
* **Conclusion:** FAT16 is the file system used by DOS.
#### 491. The program is known as \_\_\_\_\_\_ which interacts with the inner part of called kernel.
1. Compiler
2. Protocol
3. Device Driver
4. Shell
Show me the answer
**Answer:** 4. Shell
**Explanation:**
* **Shell:** The shell is a program that acts as an interface between the user and the kernel. It interprets user commands and passes them to the kernel for execution.
* **Conclusion:** The shell interacts with the kernel to execute user commands.
#### 492. The time taken by the disk arm to locate the specific address of a sector for getting information is called \_\_\_\_\_\_.
1. Rotational Latency
2. Search Time
3. Seek Time
4. Response Time
Show me the answer
**Answer:** 3. Seek Time
**Explanation:**
* **Seek Time:** Seek time is the time taken by the disk arm to move to the specific track where the data is located.
* **Conclusion:** Seek time is the time required to position the disk arm.
#### 493. Which file system does Windows 95 typically use?
1. FAT16
2. NTFS
3. FAT32
4. LMFS
Show me the answer
**Answer:** 3. FAT32
**Explanation:**
* **Windows 95 File System:** Windows 95 primarily uses the FAT32 file system, which supports larger disk sizes and more efficient storage compared to FAT16.
* **Conclusion:** FAT32 is the default file system for Windows 95.
#### 494. Identify the odd thing in the services of operating system.
1. Accounting
2. Error detection and correction
3. Protections
4. Deadlock handling
Show me the answer
**Answer:** 2. Error detection and correction
**Explanation:**
* **Operating System Services:** Accounting, protection, and deadlock handling are standard services provided by an operating system. Error detection and correction are typically handled by hardware or specific software, not the OS.
* **Conclusion:** Error detection and correction are not primary OS services.
#### 495. Cryptography technique is used in \_\_\_\_\_\_.
1. Polling
2. Protection
3. Job Scheduling
4. File Management
Show me the answer
**Answer:** 2. Protection
**Explanation:**
* **Cryptography:** Cryptography is used to secure data and communications, providing protection against unauthorized access and ensuring data integrity.
* **Conclusion:** Cryptography is primarily used for protection.
#### 496. Which of the following is not an advantage of multiprogramming?
1. Increased throughput
2. Shorter response times
3. Decreased operating system overhead
4. Ability to assign priorities to jobs
Show me the answer
**Answer:** 3. Decreased operating system overhead
**Explanation:**
* **Multiprogramming:** Multiprogramming increases throughput and allows for priority-based scheduling. However, it increases operating system overhead due to the need for process management and context switching.
* **Conclusion:** Decreased operating system overhead is not an advantage of multiprogramming.
#### 497. In \_\_\_\_\_\_ OS, the response time is very critical.
1. Multitasking
2. Online
3. Batch
4. Real-time
Show me the answer
**Answer:** 4. Real-time
**Explanation:**
* **Real-Time OS:** In real-time operating systems, response time is critical as tasks must be completed within strict deadlines.
* **Conclusion:** Real-time systems prioritize response time.
#### 498. An optimal scheduling algorithm in terms of minimizing the average waiting time of a given set of processes is \_\_\_\_\_\_.
1. FCFS scheduling algorithm
2. Round robin scheduling algorithm
3. Shortest job-first scheduling algorithm
4. None of the above
Show me the answer
**Answer:** 3. Shortest job-first scheduling algorithm
**Explanation:**
* **SJF Scheduling:** The Shortest Job First (SJF) scheduling algorithm minimizes the average waiting time by prioritizing shorter jobs.
* **Conclusion:** SJF is optimal for minimizing average waiting time.
#### 499. Real-time systems are \_\_\_\_\_\_.
1. Primarily used on mainframe computers
2. Used for monitoring events as they occur
3. Used for program development
4. Used for real-time interactive users
Show me the answer
**Answer:** 2. Used for monitoring events as they occur
**Explanation:**
* **Real-Time Systems:** Real-time systems are designed to monitor and respond to events as they occur, often within strict time constraints.
* **Conclusion:** Real-time systems are used for event monitoring.
#### 500. Which technique was introduced because a single job could not keep both the CPU and the I/O devices busy?
1. Time-sharing
2. Preemptive scheduling
3. Spooling
4. Multiprogramming
Show me the answer
**Answer:** 4. Multiprogramming
**Explanation:**
* **Multiprogramming:** Multiprogramming allows multiple jobs to reside in memory simultaneously, ensuring that the CPU and I/O devices are kept busy.
* **Conclusion:** Multiprogramming improves resource utilization.
#### 501. Inter-process communication can be done through \_\_\_\_\_\_.
1. Mail
2. System calls
3. Messages
4. Traps
Show me the answer
**Answer:** 3. Messages
**Explanation:**
* **Inter-Process Communication (IPC):** IPC mechanisms include message passing, shared memory, and pipes. Messages are a common method for processes to communicate.
* **Conclusion:** Messages are used for inter-process communication.
#### 502. In Priority Scheduling, a priority number (integer) is associated with each process. The CPU is allocated to the process with the highest priority (smallest integer = highest priority). The problem of starvation (low priority processes may never execute) is resolved by \_\_\_\_\_\_.
1. Terminating the process
2. Mutual Exclusion
3. Aging
4. Semaphore
Show me the answer
**Answer:** 3. Aging
**Explanation:**
* **Aging:** Aging is a technique used to prevent starvation by gradually increasing the priority of long-waiting processes.
* **Conclusion:** Aging resolves the problem of starvation in priority scheduling.
#### 503. CPU performance is measured through \_\_\_\_\_\_.
1. Throughput
2. Flops
3. MHz
4. None of the above
Show me the answer
**Answer:** 1. Throughput
**Explanation:**
* **Throughput:** Throughput measures the number of processes completed per unit time and is a key metric for CPU performance.
* **Conclusion:** Throughput is used to measure CPU performance.
#### 504. PCB = \_\_\_\_\_\_.
1. Program Control Block
2. Process Communication Block
3. Process Control Block
4. None of the above
Show me the answer
**Answer:** 3. Process Control Block
**Explanation:**
* **PCB:** The Process Control Block (PCB) is a data structure used by the operating system to store information about a process, such as its state, program counter, and registers.
* **Conclusion:** PCB stands for Process Control Block.
#### 505. Software is a program that directs the overall operation of the computer, facilitates its use, and interacts with the user. What are the different types of this software?
1. Operating system
2. Utilities
3. Language Compiler
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **Software Types:** The software that directs the overall operation of a computer includes the operating system, utilities, and language compilers.
* **Conclusion:** All the listed types are part of system software.
#### 506. A \_\_\_\_\_\_ is software that manages the time of a microprocessor to ensure that all time-critical events are processed as efficiently as possible. This software allows the system activities to be divided into multiple independent elements called tasks.
1. Kernel
2. Processor
3. Shells
4. Device Driver
Show me the answer
**Answer:** 1. Kernel
**Explanation:**
* **Kernel:** The kernel is the core component of an operating system that manages system resources and ensures efficient processing of time-critical events.
* **Conclusion:** The kernel manages microprocessor time and system tasks.
#### 507. The primary job of the operating system of a computer is to \_\_\_\_\_\_.
1. Command Resources
2. Provide Utilities
3. Manage Resources
4. Be user-friendly
Show me the answer
**Answer:** 3. Manage Resources
**Explanation:**
* **Operating System Role:** The primary job of an operating system is to manage hardware and software resources, such as CPU, memory, and I/O devices.
* **Conclusion:** Resource management is the primary function of an OS.
#### 508. With the round-robin CPU scheduling in a time-shared system \_\_\_\_\_\_.
1. Using very large time slices 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 slices degenerates into the first-come-first-served algorithm
**Explanation:**
* **Round Robin Scheduling:** If the time slice is very large, round-robin scheduling behaves like FCFS, as each process completes before the next one starts.
* **Conclusion:** Large time slices make round-robin similar to FCFS.
#### 509. 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 the listed criteria are used to evaluate scheduling algorithms.
#### 510. Which of the following is contained in Process Control Block (PCB)?
1. Process Number
2. Memory Limits
3. List of Open Files
4. All of the Above
Show me the answer
**Answer:** 4. All of the Above
**Explanation:**
* **PCB Contents:** The Process Control Block (PCB) contains information such as the process number, memory limits, and a list of open files.
* **Conclusion:** All the listed items are part of the PCB.
#### 511. Supercomputers typically employ \_\_\_\_\_\_.
1. Real-time Operating system
2. Desktop OS
3. Multiprocessors OS
4. None of the above
Show me the answer
**Answer:** 3. Multiprocessors OS
**Explanation:**
* **Supercomputers:** Supercomputers use multiprocessor operating systems to manage multiple CPUs and achieve high performance.
* **Conclusion:** Multiprocessor OS is used in supercomputers.
#### 512. Round-robin scheduling is essentially \_\_\_\_\_\_ the preemptive version of \_\_\_\_\_\_.
1. FIFO
2. Shortest remaining
3. Shortest job first
4. Longest time first
Show me the answer
**Answer:** 1. FIFO
**Explanation:**
* **Round Robin:** Round-robin scheduling is a preemptive version of FIFO, where each process is given a fixed time slice.
* **Conclusion:** Round-robin is a preemptive FIFO.
#### 513. A page fault occurs.
1. When the page is not in the memory
2. When the page is in the memory
3. When the process enters the blocked state
4. When the process is in the ready state
Show me the answer
**Answer:** 1. When the page is not in the memory
**Explanation:**
* **Page Fault:** A page fault occurs when a process tries to access a page that is not currently in main memory.
* **Conclusion:** Page faults occur when the required page is not in memory.
#### 514. Which of the following will determine your choice of systems software for your computer?
1. Is the applications software you want to use compatible with it?
2. Is it expensive?
3. Is it compatible with your hardware?
4. Both (A) and (C)
Show me the answer
**Answer:** 4. Both (A) and (C)
**Explanation:**
* **System Software Choice:** The choice of system software depends on compatibility with both applications software and hardware.
* **Conclusion:** Both compatibility with applications and hardware are important factors.
#### 515. Let S and Q be two semaphores initialized to 1, where P0 and P1 processes the following statements: wait(S); wait(Q); —; signal(S); signal(Q) and wait(Q); wait(S); —; signal(Q); signal(S); respectively. The above situation depicts a \_\_\_\_\_\_.
1. Semaphore
2. Signal
3. Deadlock
4. Interrupt
Show me the answer
**Answer:** 3. Deadlock
**Explanation:**
* **Deadlock:** The processes P0 and P1 are waiting for each other to release semaphores S and Q, leading to a deadlock.
* **Conclusion:** The situation depicts a deadlock.
#### 516. What is a shell?
1. It is a hardware component
2. It is a part in compiler
3. It is a command interpreter
4. It is a tool in CPU scheduling
Show me the answer
**Answer:** 3. It is a command interpreter
**Explanation:**
* **Shell:** The shell is a command interpreter that allows users to interact with the operating system by executing commands.
* **Conclusion:** The shell acts as a command interpreter.
#### 517. Routine is not loaded until it is called. All routines are kept on disk in a relocatable load format. The main program is loaded into memory & is executed. This type of loading is called \_\_\_\_\_\_.
1. Static loading
2. Dynamic linking
3. Dynamic loading
4. Overlays
Show me the answer
**Answer:** 3. Dynamic loading
**Explanation:**
* **Dynamic Loading:** Dynamic loading allows routines to be loaded into memory only when they are called, improving memory utilization.
* **Conclusion:** This is an example of dynamic loading.
#### 518. In the blocked state:
1. The processes waiting for I/O are found
2. The process which is running is found
3. The processes waiting for the processor are found
4. None of the above
Show me the answer
**Answer:** 1. The processes waiting for I/O are found
**Explanation:**
* **Blocked State:** Processes in the blocked state are waiting for I/O operations to complete.
* **Conclusion:** Blocked processes are waiting for I/O.
#### 519. What is the memory from 1K - 640K called?
1. Extended Memory
2. Low Memory
3. Normal Memory
4. Conventional Memory
Show me the answer
**Answer:** 4. Conventional Memory
**Explanation:**
* **Conventional Memory:** The memory range from 1K to 640K is called conventional memory and is used by DOS and early operating systems.
* **Conclusion:** This memory range is known as conventional memory.
#### 520. The process related to process control, file management, device management, information about system and communication that is requested by any higher-level language can be performed by \_\_\_\_\_\_.
1. Editors
2. System Call
3. Compilers
4. Caching
Show me the answer
**Answer:** 2. System Call
**Explanation:**
* **System Calls:** System calls provide an interface for higher-level languages to request services from the operating system, such as process control, file management, and device management.
* **Conclusion:** System calls handle these requests.
#### 521. If the Disk head is located initially at 32, find the number of disk moves required with FCFS if the disk queue of I/O blocks requests are 98, 37, 14, 124, 65, 67.
1. 310
2. 315
3. 324
4. 321
Show me the answer
**Answer:** 4. 321
**Explanation:**
* **FCFS Disk Scheduling:** The disk arm moves in the order of requests: 32 → 98 → 37 → 14 → 124 → 65 → 67.
* **Total Moves:**
* 32 → 98: $$|32 - 98| = 66$$
* 98 → 37: $$|98 - 37| = 61$$
* 37 → 14: $$|37 - 14| = 23$$
* 14 → 124: $$|14 - 124| = 110$$
* 124 → 65: $$|124 - 65| = 59$$
* 65 → 67: $$|65 - 67| = 2$$
* **Total:** $$66 + 61 + 23 + 110 + 59 + 2 = 321$$
* **Conclusion:** The total number of disk moves is 321.
#### 522. Multiprogramming systems \_\_\_\_\_\_.
1. Are easier to develop than single programming systems
2. Execute each job faster
3. Execute more jobs in the same time
4. Are used only on large mainframe computers
Show me the answer
**Answer:** 3. Execute more jobs in the same time
**Explanation:**
* **Multiprogramming:** Multiprogramming allows multiple jobs to reside in memory simultaneously, increasing system throughput.
* **Conclusion:** Multiprogramming executes more jobs in the same time.
#### 523. Which is not the state of the process?
1. Blocked
2. Ready
3. Running
4. Privileged
Show me the answer
**Answer:** 4. Privileged
**Explanation:**
* **Process States:** The primary states of a process are blocked, ready, and running. Privileged is not a process state.
* **Conclusion:** Privileged is not a process state.
#### 524. The solution to the Critical Section Problem is: Mutual Exclusion, Progress, and Bounded Waiting.
1. The statement is false
2. The statement is contradictory
3. The statement is true
4. None of the above
Show me the answer
**Answer:** 3. The statement is true
**Explanation:**
* **Critical Section Problem:** The solution to the critical section problem requires mutual exclusion, progress, and bounded waiting.
* **Conclusion:** The statement is true.
#### 525. The problem of thrashing is affected significantly by \_\_\_\_\_\_.
1. Program structure
2. Primary storage size
3. Program size
4. None of the above
Show me the answer
**Answer:** 1. Program structure
**Explanation:**
* **Thrashing:** Thrashing occurs when the system spends more time swapping pages than executing processes. It is influenced by the program's memory access patterns (program structure).
* **Conclusion:** Program structure significantly affects thrashing.
#### 526. The state of a process after it encounters an I/O instruction is \_\_\_\_\_\_.
1. Ready
2. Idle
3. Blocked/Waiting
4. Running
Show me the answer
**Answer:** 3. Blocked/Waiting
**Explanation:**
* **I/O Instruction:** When a process encounters an I/O instruction, it moves to the blocked/waiting state until the I/O operation completes.
* **Conclusion:** The process enters the blocked/waiting state.
#### 527. The number of processes completed per unit time is known as \_\_\_\_\_\_.
1. Output
2. Efficiency
3. Throughput
4. Capacity
Show me the answer
**Answer:** 3. Throughput
**Explanation:**
* **Throughput:** Throughput measures the number of processes completed per unit time.
* **Conclusion:** Throughput is the correct term.
#### 528. \_\_\_\_\_\_ is the situation in which a process is waiting on another process, which is also waiting on another process ... which is waiting on the first process. None of the processes involved in this circular wait are making progress.
1. Deadlock
2. Dormant
3. Starvation
4. None of the above
Show me the answer
**Answer:** 1. Deadlock
**Explanation:**
* **Deadlock:** Deadlock occurs when processes are waiting for each other in a circular chain, preventing any progress.
* **Conclusion:** This situation describes deadlock.
#### 529. Which technique was introduced because a single job could not keep both the CPU and the I/O devices busy?
1. Time-sharing
2. Preemptive scheduling
3. Spooling
4. Multiprogramming
Show me the answer
**Answer:** 4. Multiprogramming
**Explanation:**
* **Multiprogramming:** Multiprogramming allows multiple jobs to reside in memory, ensuring that the CPU and I/O devices are kept busy.
* **Conclusion:** Multiprogramming improves resource utilization.
#### 530. The mechanism that brings a page into memory only when it is needed is called \_\_\_\_\_\_.
1. Segmentation
2. Demand Paging
3. Fragmentation
4. Page Replacement
Show me the answer
**Answer:** 2. Demand Paging
**Explanation:**
* **Demand Paging:** Demand paging loads pages into memory only when they are needed, reducing memory usage.
* **Conclusion:** This mechanism is called demand paging.
#### 531. Switching the CPU to another Process requires saving the state of the old process and loading the new process state. This is called as \_\_\_\_\_\_.
1. Process Blocking
2. Time Sharing
3. Context Switch
4. None of the above
Show me the answer
**Answer:** 3. Context Switch
**Explanation:**
* **Context Switch:** A context switch involves saving the state of the current process and loading the state of the next process.
* **Conclusion:** This process is called a context switch.
#### 532. Which directory implementation is used in most Operating Systems?
1. Single level directory structure
2. Tree directory structure
3. Two level directory structure
4. Acyclic directory structures
Show me the answer
**Answer:** 2. Tree directory structure
**Explanation:**
* **Directory Implementation:** Most operating systems use a tree directory structure, which allows for hierarchical organization of files and directories.
* **Conclusion:** The tree directory structure is widely used.
#### 533. The Banker’s algorithm is used:
1. To prevent deadlock in operating systems
2. To detect deadlock in operating systems
3. To rectify a deadlocked state
4. None of the above
Show me the answer
**Answer:** 1. To prevent deadlock in operating systems
**Explanation:**
* **Banker’s Algorithm:** The Banker’s algorithm is used to prevent deadlock by ensuring that the system is always in a safe state.
* **Conclusion:** It is used for deadlock prevention.
#### 534. A thread:
1. Is a lightweight process where the context switching is low
2. Is a lightweight process where the context switching is high
3. Is used to speed up paging
4. None of the above
Show me the answer
**Answer:** 1. Is a lightweight process where the context switching is low
**Explanation:**
* **Thread:** A thread is a lightweight process that shares resources with other threads in the same process. Context switching between threads is faster than between processes.
* **Conclusion:** Threads have low context switching overhead.
#### 535. \_\_\_\_\_\_ is a high-level abstraction over Semaphore.
1. Shared memory
2. Monitor
3. Message passing
4. Mutual exclusion
Show me the answer
**Answer:** 2. Monitor
**Explanation:**
* **Monitor:** A monitor is a high-level synchronization construct that encapsulates shared resources and provides controlled access to them.
* **Conclusion:** Monitors abstract over semaphores.
#### 536. A tree-structured file directory system \_\_\_\_\_\_.
1. Allows easy storage and retrieval of file names
2. Is a much-debated unnecessary feature
3. Is not essential when we have millions of files
4. None of the above
Show me the answer
**Answer:** 1. Allows easy storage and retrieval of file names
**Explanation:**
* **Tree Directory Structure:** A tree-structured directory system organizes files hierarchically, making it easier to store and retrieve files.
* **Conclusion:** It simplifies file management.
#### 537. Translator for low-level programming language were termed as:
1. Assembler
2. Linker
3. Compiler
4. Loader
Show me the answer
**Answer:** 1. Assembler
**Explanation:**
* **Assembler:** An assembler translates low-level assembly language into machine code.
* **Conclusion:** Assemblers are used for low-level languages.
#### 538. Analysis which determines the meaning of a statement once its grammatical structure becomes known is termed as:
1. Semantic analysis
2. Regular analysis
3. Syntax analysis
4. General analysis
Show me the answer
**Answer:** 1. Semantic analysis
**Explanation:**
* **Semantic Analysis:** Semantic analysis determines the meaning of a statement after its syntax is understood.
* **Conclusion:** This is called semantic analysis.
#### 539. Load address for the first word of the program is called:
1. Linker address origin
2. Phase library
3. Load address origin
4. Absolute library
Show me the answer
**Answer:** 3. Load address origin
**Explanation:**
* **Load Address Origin:** The load address origin is the starting address where the first word of the program is loaded.
* **Conclusion:** This is called the load address origin.
#### 540. Symbolic names can be associated with:
1. Information
2. Operand
3. Data or instruction
4. Mnemonic operation
Show me the answer
**Answer:** 3. Data or instruction
**Explanation:**
* **Symbolic Names:** Symbolic names are used to represent data or instructions in assembly language.
* **Conclusion:** Symbolic names are associated with data or instructions.
#### 541. The translator which performs macro expansion is called a:
1. Macro processor
2. Micro pre-processor
3. Macro pre-processor
4. Assembler
Show me the answer
**Answer:** 1. Macro processor
**Explanation:**
* **Macro Processor:** A macro processor expands macros into their corresponding code during assembly.
* **Conclusion:** This is called a macro processor.
#### 542. Shell is the exclusive feature of:
1. UNIX
2. System software
3. DOS
4. Application software
Show me the answer
**Answer:** 1. UNIX
**Explanation:**
* **Shell:** The shell is a command interpreter primarily associated with UNIX-based operating systems.
* **Conclusion:** The shell is a feature of UNIX.
#### 543. A program in execution is called:
1. Process
2. Procedure
3. Instruction
4. Function
Show me the answer
**Answer:** 1. Process
**Explanation:**
* **Process:** A process is a program in execution.
* **Conclusion:** This is called a process.
#### 544. Interval between the time of submission and completion of the job is called:
1. Waiting time
2. Throughput
3. Turnaround time
4. Response time
Show me the answer
**Answer:** 3. Turnaround time
**Explanation:**
* **Turnaround Time:** Turnaround time is the total time taken from job submission to completion.
* **Conclusion:** This is called turnaround time.
#### 545. A scheduler which selects processes from secondary storage device is called:
1. Short-term scheduler
2. Medium-term scheduler
3. Long-term scheduler
4. Process scheduler
Show me the answer
**Answer:** 3. Long-term scheduler
**Explanation:**
* **Long-Term Scheduler:** The long-term scheduler selects processes from secondary storage and loads them into memory.
* **Conclusion:** This is the long-term scheduler.
#### 546. The scheduling in which CPU is allocated to the process with the least CPU-burst time is called:
1. Priority Scheduling
2. Round Robin Scheduling
3. Shortest job-first Scheduling
4. Multilevel Queue Scheduling
Show me the answer
**Answer:** 3. Shortest job-first Scheduling
**Explanation:**
* **SJF Scheduling:** Shortest Job First (SJF) scheduling allocates the CPU to the process with the shortest CPU burst time.
* **Conclusion:** This is called SJF scheduling.
#### 547. The term ‘page traffic’ describes:
1. Number of pages in memory at a given instant
2. Number of papers required to be brought in at a given page request
3. The movement of pages in and out of memory
4. Number of pages of executing programs loaded in memory
Show me the answer
**Answer:** 3. The movement of pages in and out of memory
**Explanation:**
* **Page Traffic:** Page traffic refers to the movement of pages between memory and secondary storage.
* **Conclusion:** This describes page traffic.
#### 548. The “turn-around” time of a user job is the:
1. Time since its submission to the time its results become available
2. Time duration for which the CPU is allotted to the job
3. Total time taken to execute the job
4. Time taken for the job to move from assembly phase to completion phase
Show me the answer
**Answer:** 1. Time since its submission to the time its results become available
**Explanation:**
* **Turnaround Time:** Turnaround time is the total time from job submission to completion.
* **Conclusion:** This is the correct definition.
#### 549. Which of the following can be used as a criterion for classification of data structures used in language processing?
1. Nature of a data structure
2. Lifetime of a data structure
3. Purpose of a data structure
4. All of the above
Show me the answer
**Answer:** 4. All of the above
**Explanation:**
* **Data Structure Classification:** Data structures can be classified based on their nature, lifetime, and purpose.
* **Conclusion:** All the listed criteria are valid.
#### 550. Memory utilization factor shall be computed as follows:
1. Memory in use/allocated memory
2. Memory in use/total memory connected
3. Memory allocated/free existing memory
4. Memory committed/total memory available
Show me the answer
**Answer:** 1. Memory in use/allocated memory
**Explanation:**
* **Memory Utilization:** Memory utilization is calculated as the ratio of memory in use to allocated memory.
* **Conclusion:** This is the correct formula.
#### 550. Memory utilization factor shall be computed as follows:
1. Memory in use/allocated memory
2. Memory in use/total memory connected
3. Memory allocated/free existing memory
4. Memory committed/total memory available
Show me the answer
**Answer:** 1. Memory in use/allocated memory
**Explanation:**
* **Memory Utilization Factor:** The memory utilization factor measures how efficiently memory is being used. It is calculated as the ratio of memory in use to the total allocated memory.
* **Conclusion:** Memory utilization factor is computed as memory in use divided by allocated memory.