.jpg "gate questions on operating system with answers pdf")
1. When the page fault rate is low
-
the turnaround time increases
the effective access time increases
the effective access time decreases
2. An edge from process Pi to Pj in a wait for graph indicates that
-
pi is waiting for pj to release a resource that pi needs
pj is waiting for pi to release a resource that pj needs
pi is waiting for pj to leave the system
3. Swapping be done when a process has pending I/O, or has to execute I/O operations only into operating system buffers.
-
must
can
must never
4. The usefulness of signals as a general inter process communication mechanism is limited because
-
they do not work between processes
they are user generated
they cannot carry information directly
5. Which of the following condition(s) is/are required for a deadlock to be possible?
-
mutual exclusion
a process may hold allocated resources while awaiting
no resource can be forcibly removed from a process
6. The model in which one kernel thread is mapped to many user-level threads is called
-
many to one model
one to many model
many to many model
7. Which of the following page replacement algorithms suffers from Belady’s Anomaly?
-
optimal replacement
lru
fifo
8. In question 2, if the number of page frames is increased to 4, then the number of page transfers
-
decreases
increases
remains the same
9. A memory page containing a heavily used variable that was initialized very early and is in constant use is removed, then the page replacement algorithm used is
-
lru
lfu
fifo
10. Users that their processes are running on a paged system.
-
are aware
are unaware
may unaware
11. The wait-for graph is a deadlock detection algorithm that is applicable when
-
all resources have a single instance
all resources have multiple instances
all resources have a single 7 multiple instances
12. The content of the matrix Need is
-
allocation – available
max – available
max – allocation
13. The data structures available in the Banker’s algorithm are
-
available
need
allocation
14. In the Many to One model, if a thread makes a blocking system call
-
the entire process will be blocked
a part of the process will stay blocked, with the rest running
the entire process will run
15.If the offset is legal
-
it is used as a physical memory address itself
it is subtracted from the segment base to produce the physical memory address
it is added to the segment base to produce the physical memory address
16. Which of the following system calls does not return control to the calling point, on termination?
-
fork
exec
ioctl
17. File type can be represented by
-
file name
file extension
file identifier
18. In virtual memory, which is not a page replacement algorithm ?
-
FIFO
BFS
LRU
19. The larger the block size, the the internal fragmentation.
-
greater
lesser
same
20. Which of the following is FALSE?
-
context switch time is longer for kernel level threads than for user level threads
user level threads do not need any hardware support
related kernel level threads can be scheduled on different processors in a multiprocessor system
21. Thrashing the CPU utilization.
-
increases
keep constant
decreases
22. The child process completes execution, but the parent keeps executing, then the child process is known as
-
Orphan
Zombie
Body
23. A Process Control Block(PCB) does not contain which of the following?
-
Code
Stack
Bootstrap Program
24. If one thread opens a file with read privileges then
-
other threads in the another process can also read from that file
other threads in the same process can also read from that file
any other thread can not read from that file
25. A thread is also called
-
light weight process(lwp)
heavy weight process(hwp)
process
26. The model in which one user-level thread is mapped to many kernel level threads is called
-
many to one model
one to many model
many to many model
27. The time taken to move the disk arm to the desired cylinder is called the
-
positioning time
random access time
seek time
28. Operating System maintains the page table for
-
each process
each thread
each instruction
29. What is the idea behind thread pools?
-
a number of threads are created at process startup and placed in a pool where they sit and wait for work
when a process begins, a pool of threads is chosen from the many existing and each thread is allotted equal amount of work
all threads in a pool distribute the task equally among themselves
30. The time taken for the desired sector to rotate to the disk head is called
-
positioning time
random access time
seek time
Post a Comment
0 Comments