Mid NOS

Which of the following best defines an operating system ?. Software used to connect hardware devices directly. A system that allows applications to run and manage hardware resources. A utility that cleans up system memory. A language compiler.

The kernal in an Operating system is : A user-level application program. The part of the OS that interacts directly with hardware. A database management subsystem. A file system utility.

In a computer system , the CPU memory , and I/O devices collectively form the : Application Layer. Hardware Layer. User Interface. File system.

The OS functions as a resource allocator primarily to : A Distribute CPU cycles and memory among users. Manage database storage. Handle user logins only. Translate high-level languages.

The main purpose of interrupts in a computer system is to : Increase CPU clock speed. Allow asynchronous communication between devices and CPU. Halt system execution permanently. Switch from user mode to kernal mode.

In the context of storage , DRAM is considered. Non-volatile primary memory. Magnetic tertiary storage. Volatile primary memory. Optical storage.

Which of the following describes the von Neumann architecture?. A model using separate memory for instructions and data. A system where CPU fetches both instructions and data from a single memory unit. A parallel multi-core design. A system based only on cache memory.

The direct Memory Access (DMA) technique is used to : Increase CPU frequency. Allow I/O devices to transfer data directly to memory. Enable multitasking. Manage virtual memory.

Multiprogramming improves CPU utilization by : Allowing only one process at a time. Switching between jobs when one waits for I/O. Running multiple CPUs in parallel. Storing data permanently on disk.

Timesharing systems are are characterized by : Sequential execution of batch jobs. Quick process switching for interactive user response. Real-time industrial control. Single-user , single-task operation.

The OS component responsible for tracking memory allocation and deallocation is: Process scheduler. Memory manager. File handler. Disk controller.

Which of the following best describes a process ?. A program stored on disk. A passive executable file. A program in execution with resources assigned. A system utility.

The dual-mode operation in operating systems ensures: Automatic user logins. Separation between user-level and privileged instructions. Equal access for all users. Automatic recovery after power loss.

A system call is used to : interrupt a process forcibly. Request a service from the operating system. Reboot the system. Switch between devices.

In storage hierarchy , which level is fastest but smallest ?. Cache memory. Main memory. Hard disk. Magnetic tape.

Cache memory is used to : Increase permanent storage capacity. Store Frequently accessed data for quick retrieval. Replace hard disks. Convert analog signals into digital form.

Protection mechanisms in an operating system are mainly designed to: increase computation speed. Restrict unauthorized access to resources. Compress data efficiently. Organize files alphabetically.

Security in an Operating system includes. Controlling CPU scheduling. Defending against malware and unauthorized access. Managing cache coherency. Formatting secondary storage.

Which of the following is an example of a modern computing environment supported by operating systems?. Stand-alone calculator. Mobile and cloud-based platforms. Magnetic tape systems. Typewriter-based control.

In a cloud computing environment , the OS supports virtualization primarily through : Virtual Machine Monitors (VMMs). Devices controllers. Application interfaces only. Cache replacement policies.

The Operating system acts as a bridge between: CPU and RAM. Hardware and users. Compiler and debugger. Database and network.

The kernal of an operating system is : The outer shell of the system. The central part that manages system resources. A graphical user interface. A file management tool.

The four main components of a computer system are: CPU , users , cache , network. Hardware , operating system , application programs , users. Hardware , software , printers , users. Memory , CPU , files , keyboard.

Which of the following correctly defines the OS's role as a control program?. It converts code to machine language. It oversees program execution to avoid interference and errors. It compiles user programs. It performs arithmetic operations.

Interrupts are essential because they : Allow a process to execute continously. Enable The CPU to respond to external or internal events. Prevent the CPU from executing instructions. Disable hardware controllers.

When a device finishes its operations , it signals the CPU by. Polling. Interrupt request. Memory fetch. Context switch.

The storage hierarchy arranges memory according to : File system structure. Speed , cost and volatility. Device driver type. Network topology.

Which storage type is volatile ?. Magnetic disk. Flash memory. DRAM. Optical disk.

The von Neumann architecture is based on : Separate data and instruction memories. A single memory for data and instructions. Multiple control units. Hardware-only scheduling.

Direct Memory Access (DMA) improves efficiency by : Replacing main memory. Allowing devices to transfer data directly to memory without CPU involvement. Slowing down I/O processing. Reducing main-memory capacity.

Asymmetric multiprocessing differs from symmetric multiprocessing because : All processors execute identical tasks. Each processor is assigned specific tasks. The system uses only one CPU. It requires no OS coordination.

The bootstrap program is responsible for : Formatting the disk. Initializing hardware and loading the kernal. Managing user accounts. Compiling source code.

Virtual memory allows a process to : Execute without being fully loaded into main memory. Bypass the CPU scheduler. Eliminate I/O operations. Increase physical memory.

Dual-mode operation ensures system security by : Restricting kernal access to privileged instructions. Allowing all users full hardware access. increasing CPU speed. Eliminating the need for interrupts.

The primary function of the process scheduler is to : Translate high-level languages. Decide which process runs next. Manage hard-disk partitions. Detect memory errors.

Caching improves performance by : Deleting redundant data. Storing frequently used data in faster memory. Compressing files. Managing power consumption.

Cache coherency is particularly important in : Single-processor systems. Multiprocessor or distributed systems. Batch processing. Embedded systems.

Protection in operating systems is best described as: Data backup management. Controlling access to system resources. Error correction in files. Power-supply monitoring.

Security measures primarily focus on : Optimizing cache replacement. Defending against internal and external threats. Organizing user directions. Speeding up computation.

In cloud computing , the OS provides virtualization support through : Firewalls and anti-virus software. Virtual Machine Monitors (VMMs) and resource isolation. Local compilers. Physical hardware controllers.

What is a process ?. A passive file on disk. A program in execution. A hardware thread. A kernal routine.

Which section contains global variables ?. Stack. Text. Data. Heap.

Which process state means "waiting for CPU"?. Running. New. Ready. Terminated.

Which of the following is not stored in the Process Control Block (PCB)?. Program Counter. CPU Registers. Cache Memory. I/O status.

Which memory component grows dynamically during program execution?. Stack. Heap. Data. Text.

In Linux, PID refers to : Parent process ID. Process identifier. CPU core number. Priority value.

Which scheduler runs most frequently?. Long-term scheduler. Medium-term scheduler. Short-term scheduler. Foreground scheduler.

Which queue stores all processes in the system?. Ready Queue. Device Queue. Job Queue. Wait Queue.

Which scheduler swaps processes to disk to reduce multiprogramming?. Short-term scheduler. Medium-term scheduler. Long-term scheduler. Foreground scheduler.

Why is context switching considered overhead?. CPU runs faster during switching. No useful work is done during the switch. Registers are deleted. PCB is destroyed.

Which UNIX system call is used to create a new process?. create(). fork(). exec(). spawn().

Which system call replaces a process's memory space with a new program ?. fork(). exec(). kill(). exit().

A process that has terminated but still occupies an entry in the process table is called: Zombie. Orphan. Daemon. Kernel thread.

Which IPC mechanism uses shared variables?. Pipes. RPC. Shared Memory. Mailbox.

Which IPC mechanism does not rely on shared memory ?. Shared Memory. Message Passing. POSIX. Buffering.

In the producer-consumer shared memory problem , if in == out , the buffer is : Full. Empty. Overflowing. Invalid.

Which communication method uses send() and receive() operations?. Message Passing. Shared Memory. Forking. Paging.

A mailbox is used in which type of communication?. Direct communication. Indirect communication. Shared memory. Multithreading.

In blocking send mode , the sender : Continues execution immediately. Waits until the message is received. Terminates. Loses the message.

A zero-capacity message queue implies : Infinite buffer. Rendezvous-style communication. Deadlock. Lossy communication.

POSIX shared memory uses which function?. shm_open(). fork(). socket(). fopen().

Mach IPC uses which function for sending messages ?. shm_open(). msg_send(). pipe(). thread_send().

Windows uses which mechanism for inter-process messaging?. LPC. RPC. UDP. POSIX.

A socket is uniquely identified using: Only IP address. Only port number. IP address + Port number. Process ID.

TCP sockets are: Connectionless. Datagram-based. Steam-based. Mutlicast only.

in RPC , stubs are responsible for : Page fault handling. Client-server communication. Context switching. Scheduling.

Ordinary pipes require: Network connections. Parent-child relationship. Mailboxes. RPC setup.

Named pipes allow communication between. Only parent and child. Only kernel-level threads. unrelated processes. Processes on different machines.

Which IPC mechanism is unidirectional by default?. Ordinary Pipe. Socket. RPC. Thread.

Which scheduler balances the mix of I/O-bound and CPU-bound processes?. Long-term scheduler. Short-term scheduler. Medium-term scheduler. Foreground scheduler.