BPSC TRE Operating Systems – Full-Length Mock Test Set 2

Option B is correct. In a Microkernel architecture (e.g., Mach, QNX), only core functions like minimal process management, IPC, and low-level memory management reside in kernel space. File systems, networking, and device drivers run as user-space servers, minimizing kernel panic risks.

Option D is correct. A system call is initiated by a software interrupt or trap (e.g., INT 0x80 or 'syscall' instruction). This trap switches the CPU mode bit from 1 (User mode) to 0 (Kernel mode) and transfers control to the system call handler via the trap vector.

Option C is correct. Type-1 hypervisors (e.g., VMware ESXi, Xen, KVM) run directly on physical hardware for enterprise performance. Type-2 hypervisors (e.g., VirtualBox, VMware Workstation) run as software applications on top of an operating system.

Option B is correct. The fork() system call creates a new child process that is an exact duplicate of the parent process. It returns 0 to the child process and the child's PID to the parent process.

Option C is correct. When a child process finishes execution, its memory resources are freed, but its entry in the process table remains to store its exit status code. Until the parent reads this exit status using wait(), the process is called a Zombie process.