2023 – Question 1 (Objective Questions)
(a) A computer system has 9 tape drives, with n processes competing for them. Each process may need 3 tape drives. The maximum value of n for which the system is guaranteed to be deadlock-free is:
(i) 9
(ii) 7
(iii) 8
(iv) 6
Answer: (ii) 7
(b) Which of the following page replacement algorithms suffers from Belady’s anomaly?
(i) Optimal replacement
(ii) LRU
(iii) FIFO
(iv) Both (a) and (c)
Answer: (iii) FIFO
(c) Scheduling a process from ready Queue to CPU is done by:
(i) Short term scheduler
(ii) Middle term scheduler
(iii) Long term scheduler
(iv) Dispatcher
Answer: (i) Short term scheduler
(d) The time to move the disk arm to the desired cylinder in hard disk is known as:
(i) rotational latency
(ii) seek time
(iii) positional time
(iv) disk time
Answer: (ii) seek time
(e) Compaction is used to solve the problem of:
(i) external fragmentation
(ii) internal fragmentation
(iii) both (a) and (c)
(iv) None of these
Answer: (i) external fragmentation
(f) ……. a technique of improving the priority of process waiting in queue for CPU allocation.
(i) starvation
(ii) Ageing
(iii) Revocation
(iv) Relocation
Answer: (ii) Ageing
(g) The CPU utilization is low when the system is:
(i) timesharing
(ii) thrashing
(iii) multiprocessing
(iv) None of the above
Answer: (ii) thrashing
(h) When a process waits indefinitely for some resources which are being used by other processes, it is called:
(i) Starvation
(ii) Demand Paging
(iii) Segmentation
(iv) None of the above
Answer: (i) Starvation
(i) Fork is used to
(i) dispatch a task
(ii) create a new job
(iii) create a new process
(iv) increase the priority of a task
Answer: (iii) create a new process
(j) Which one of the following is the deadlock avoidance algorithm?
(i) Banker’s algorithm
(ii) Round-robin algorithm
(iii) Elevator algorithm
(iv) Karn’s algorithm
Answer: (i) Banker’s algorithm
2022 – Question 1 (Choose the correct answer)
- (a) What is the difference between a multiprocessor and a multi-core system?
- Answer: A multiprocessor has multiple independent CPUs, while a multicore has multiple CPUs on a single chip sharing resources.
- (b) What is multiprogramming?
- Answer: Multiprogramming is a technique where multiple processes reside in memory concurrently, sharing the CPU.
- (c) Define jacketing.
- Answer: Jacketing is a technique for creating a wrapper or additional API around an existing program.
- (d) What operations can be performed on a semaphore?
- (i) Increment value by 1
- (ii) Decrement value by 1
- (iii) Can Increment and Decrement value by 1
- (iv) None of these
- (e) What is the difference between a page and a frame?
- Answer: A page is a fixed-size block of virtual memory, while a frame is a fixed-size block of physical memory. Pages are mapped to frames.
- (f) In contiguous memory allocation:
- (i) Each process is contained in a single contiguous section of memory
- (ii) all processes are contained in a single contiguous section of memory
- (iii) the memory space is contiguous
- (iv) None of the above
- (g) If the size of logical address space is 2 to the power of m, and a page size is 2 to the power of n addressing units, then the high order …… bits of a logical address designate the page number, and the…… low order bits designate the page offset.
- (i) m, n
- (ii) n, m
- (iii) m-n, m
- (iv) m-n, n
- (h) If the wait-for graph contains a cycle, then
- (i) a deadlock does not exist
- (ii) a deadlock exists
- (iii) the system is in a safe state
- (iv) Either deadlock exists or the system is in a safe state
- (i) When the event for which a thread is blocked occurs?
- (i) Thread moves to the ready queue
- (ii) Thread remains blocked
- (iii) Thread completes
- (iv) A new thread is provided
- (j) An I/O port typically consists of four registers – status, control, …….and….. registers.
- (i) system in, system out
- (ii) data in, data out
- (iii) flow in, flow out
- (iv) input, output