The central part of the UNIX Operating System is:

Question

UnlockIAS · Accepted Answer

Correct — B, Kernel. The kernel is the core of the UNIX operating system — it loads first at boot, runs in a protected/privileged mode, and directly manages the CPU, memory, processes, and I/O devices. Every other component (shell, utilities, user programs) sits above it and reaches the hardware only through kernel system calls.

Why the other options are wrong — (a) The shell (e.g., sh, bash) is the user-facing command interpreter that sits on top of the kernel — it parses commands and asks the kernel to carry them out; it is not the OS's core.  (c) The directory/file hierarchy and installed programs are content the kernel organises and runs — being managed by the kernel is different from being the kernel.  (d) Files are data managed via the kernel's file-system layer, not the OS's central control component.

Concept: UNIX has a layered architecture: hardware at the base, the kernel wrapped directly around it, and the shell/utilities/user programs in the outer layers. The kernel is the only layer that talks to hardware directly (via device drivers) and enforces process isolation, memory protection, and scheduling — everything else must ask it to act via system calls.

State PCS 2024 Q41 — Science & Technology PYQ with Answer

State PCS 2024 Q41 — Science & Technology PYQ with Answer