Operating System MCQs

File-system manipulation includes operations on files and directories such as create, open, read, write, and delete.
The other choices concern processor control, virtualization, or interrupt handling.

The communication service supports information exchange between processes locally or across a network.
It may be implemented with message passing, sockets, shared memory, or related mechanisms.

Error detection identifies hardware and software faults so the system can respond appropriately.
Illegal addresses and device failures are examples of conditions this service monitors.

The kernel is the privileged core that manages processors, memory, devices, and system calls.
Shells and libraries may request services, but they do not normally execute the core privileged functions.

Ordinary applications execute in user mode with restricted access to critical hardware and memory structures.
Privileged changes such as modifying page tables require controlled entry into kernel mode.

Kernel mode allows trusted operating-system code to execute privileged machine instructions.
User and workload modes do not grant direct control over protected hardware operations.

The mode bit tells the processor whether the current instruction stream has kernel or user privileges.
This separation protects the system from applications executing privileged instructions directly.

A hardware interrupt asynchronously notifies the processor that a device requires attention.
The other choices concern memory, scheduling, or program construction rather than device notification.

A divide-by-zero condition is a synchronous exception caused by the currently executing instruction.
The processor transfers control to an operating-system handler so the fault can be managed safely.

A timer interrupt prevents a user process from keeping the processor indefinitely.
When the timer expires, the operating system can preempt the process and schedule another task.

The bootstrap loader initializes enough hardware state to load the kernel into memory.
Schedulers and file tables are used after the operating system has already started.

An operating system coordinates hardware and offers common services to application programs.
Compilers, databases, and antivirus utilities perform narrower tasks rather than managing the whole computer.