Operating System MCQ Set 1
1. The process of dividing a disk into sectors that the disk controller can read and write, before a disk can store data is known as :
a) partitioning
b) swap space creation
c) low-level formatting
d) none of the mentioned
Answer
Answer: c [Reason:] None.
2. The data structue for a sector typically contains :
a) header
b) data area
c) trailer
d) all of the mentioned
Answer
Answer: d [Reason:] None.
3. The header and trailer of a sector contain information used by the disk controller such as ___ and ___
a) main section & disk identifier
b) error correcting codes (ECC) & sector number
c) sector number & main section
d) disk identifier & sector number
Answer
Answer: b [Reason:] None.
4. The two steps the operating system takes to use a disk to hold its files are _______ and ________
a) partitioning & logical formatting
b) swap space creation & caching
c) caching & logical formatting
d) logical formatting & swap space creation
Answer
Answer: a [Reason:] None.
5. The _______ program initializes all aspects of the system, from CPU registers to device controllers and the contents of main memory, and then starts the operating system.
a) main
b) bootloader
c) bootstrap
d) rom
Answer
Answer: c [Reason:] None.
6. For most computers, the bootstrap is stored in ________
a) RAM
b) ROM
c) Cache
d) Tertiary storage
Answer
Answer: b [Reason:] None.
7. A disk that has a boot partition is called a ___
a) start disk
b) end disk
c) boot disk
d) all of the mentioned
Answer
Answer: c [Reason:] None.
8. Defective sectors on disks are often known as ____
a) good blocks
b) destroyed blocks
c) bad blocks
d) none of the mentioned
Answer
Answer: c [Reason:] None.
9. In SCSI disks used in high end PCs, the controller maintains a list of ___ on the disk. The disk is initialized during ________ formatting which sets aside spare sectors not visible to the operating system.
a) destroyed blocks, high level formatting
b) bad blocks, partitioning
c) bad blocks, low level formatting
d) destroyed blocks, partitioning
Answer
Answer: c [Reason:] None.
10. The scheme used in the above question is known as _______ or ________
a) sector sparing & forwarding
b) forwarding & sector utilization
c) backwarding & forwarding
d) sector utilization & backwarding
Answer
Answer: a [Reason:] None.
11. An unrecoverable error is known as ___
a) hard error
b) tough error
c) soft error
d) none of the mentioned
Answer
Answer: a [Reason:] None.
Operating System MCQ Set 2
1. In _______ information is recorded magnetically on platters.
a) magnetic disks
b) electrical disks
c) assemblies
d) cylinders
Answer
Answer: a [Reason:] None.
2. The heads of the magnetic disk are attached to a _____ that moves all the heads as a unit.
a) spindle
b) disk arm
c) track
d) none of the mentioned
Answer
Answer: b [Reason:] None.
3. The set of tracks that are at one arm position make up a _____
a) magnetic disks
b) electrical disks
c) assemblies
d) cylinders
Answer
Answer: d [Reason:] None.
4. The time taken to move the disk arm to the desired cylinder is called the :
a) positioning time
b) random access time
c) seek time
d) rotational latency
Answer
Answer: c [Reason:] None.
5. The time taken for the desired sector to rotate to the disk head is called :
a) positioning time
b) random access time
c) seek time
d) rotational latency
Answer
Answer: d [Reason:] None.
6. When the head damages the magnetic surface, it is known as ___
a) disk crash
b) head crash
c) magnetic damage
d) all of the mentioned
Answer
Answer: b [Reason:] None.
7. A floppy disk is designed to rotate _____ as compared to a hard disk drive.
a) faster
b) slower
c) at the same speed
d) none of the mentioned
Answer
Answer: b [Reason:] None.
8. The host controller is :
a) controller built at the end of each disk
b) controller at the computer end of the bus
c) all of the mentioned
d) none of the mentioned
Answer
Answer: b [Reason:] None.
9. ______ controller sends the command placed into it, via messages to the _____ controller.
a) host, host
b) disk, disk
c) host, disk
d) disk, host
Answer
Answer: c [Reason:] None.
10. The disk bandwidth is :
a) the total number of bytes transferred
b) total time between the first request for service and the completion on the last transfer
c) the total number of bytes transferred divided by the total time between the first request for service and the completion on the last transfer
d) none of the mentioned
Answer
Answer: c [Reason:] None.
Operating System MCQ Set 3
1. Whenever a process needs I/O to or from a disk it issues a ________
a) system call to the CPU
b) system call to the operating system
c) a special procedure
d) all of the mentioned
Answer
Answer: b [Reason:] None.
2. If a process needs I/O to or from a disk, and if the drive or controller is busy then :
a) the request will be placed in the queue of pending requests for that drive
b) the request will not be processed and will be ignored completely
c) the request will be not be placed
d) none of the mentioned
Answer
Answer: a [Reason:] None.
3. Consider a disk queue with requests for I/O to blocks on cylinders :
98 183 37 122 14 124 65 67
Considering FCFS (first cum first served) scheduling, the total number of head movements is, if the disk head is initially at 53 :
a) 600
b) 620
c) 630
d) 640
Answer
Answer: d [Reason:] None.
4. Consider a disk queue with requests for I/O to blocks on cylinders :
98 183 37 122 14 124 65 67
Considering SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk head is initially at 53 :
a) 224
b) 236
c) 245
d) 240
Answer
Answer: b [Reason:] None.
5. Random access in magnetic tapes is ___ compared to magnetic disks.
a) fast
b) very fast
c) slow
d) very slow
Answer
Answer: d [Reason:] None.
6. Magnetic tape drives can write data at a speed ________ disk drives.
a) much lesser than
b) comparable to
c) much faster than
d) none of the mentioned
Answer
Answer: b [Reason:] None.
7. On media that use constant linear velocity (CLV), the _______ is uniform.
a) density of bits on the disk
b) density of bits per sector
c) the density of bits per track
d) none of the mentioned
Answer
Answer: c [Reason:] The farther a track is from the center of the disk.
8. SSTF algorithm, like SJF ____ of some requests.
a) may cause starvation
b) will cause starvation
c) does not cause starvation
d) causes aging
Answer
Answer: a [Reason:] None.
9. In the ______ algorithm, the disk arm starts at one end of the disk and moves toward the other end, servicing requests till the other end of the disk. At the other end, the direction is reversed and servicing continues.
a) LOOK
b) SCAN
c) C-SCAN
d) C-LOOK
Answer
Answer: b [Reason:] None.
10. In the _______ algorithm, the disk head moves from one end to the other , servicing requests along the way. When the head reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip.
a) LOOK
b) SCAN
c) C-SCAN
d) C-LOOK
Answer
Answer: c [Reason:] None.
11. In the ______ algorithm, the disk arm goes as far as the final request in each direction, then reverses direction immediately without going to the end of the disk.
a) LOOK
b) SCAN
c) C-SCAN
d) C-LOOK
Answer
Answer: a [Reason:] None.
Operating System MCQ Set 4
1. The three major methods of allocating disk space that are in wide use are :
a) contiguous
b) linked
c) indexed
d) all of the mentioned
Answer
Answer: d [Reason:] None.
2. In contiguous allocation :
a) each file must occupy a set of contiguous blocks on the disk
b) each file is a linked list of disk blocks
c) all the pointers to scattered blocks are placed together in one location
d) none of the mentioned
Answer
Answer: a [Reason:] None.
3. In linked allocation :
a) each file must occupy a set of contiguous blocks on the disk
b) each file is a linked list of disk blocks
c) all the pointers to scattered blocks are placed together in one location
d) none of the mentioned
Answer
Answer: b [Reason:] None.
4. In indexed allocation :
a) each file must occupy a set of contiguous blocks on the disk
b) each file is a linked list of disk blocks
c) all the pointers to scattered blocks are placed together in one location
d) none of the mentioned
Answer
Answer: c [Reason:] None.
5. On systems where there are multiple operating system, the decision to load a particular one is done by :
a) boot loader
b) boot strap
c) process control block
d) file control block
Answer
Answer: a [Reason:] None.
6. The VFS (virtual file system) activates file system specific operations to handle local requests according to their _______
a) size
b) commands
c) timings
d) file system types
Answer
Answer: d [Reason:] None.
7. The real disadvantage of a linear list of directory entries is the :
a) size of the linear list in memory
b) linear search to find a file
c) it is not reliable
d) all of the mentioned
Answer
Answer: b [Reason:] None.
8. Contiguous allocation of a file is defined by :
a) disk address of the first block & length
b) length & size of the block
c) size of the block
d) total size of the file
Answer
Answer: a [Reason:] None.
9. One difficulty of contiguous allocation is :
a) finding space for a new file
b) inefficient
c) costly
d) time taking
Answer
Answer: a [Reason:] None.
10. _______ and ________ are the most common strategies used to select a free hole from the set of available holes.
a) First fit, Best fit
b) Worst fit, First fit
c) Best fit, Worst fit
d) None of the mentioned
Answer
Answer: a [Reason:] None.
11. The first fit and best fit algorithms suffer from :
a) internal fragmentation
b) external fragmentation
c) starvation
d) all of the mentioned
Answer
Answer: b [Reason:] None.
12. To solve the problem of external fragmentation, ________ needs to be done periodically.
a) compaction
b) check
c) formatting
d) replacing memory
Answer
Answer: a [Reason:] None.
13. If too little space is allocated to a file
a) the file will not work
b) there will not be any space for the data, as the FCB takes it all
c) the file cannot be extended
d) the file cannot be opened
Answer
Answer: c [Reason:] None.
Operating System MCQ Set 5
1. A better way of contiguous allocation to extend the file size is :
a) adding an extent (another chunk of contiguous space)
b) adding an index table to the first contiguous block
c) adding pointers into the first contiguous block
d) none of the mentioned
Answer
Answer: a [Reason:] None.
2. If the extents are too large, then the problem that comes in is :
a) internal fragmentation
b) external fragmentation
c) starvation
d) all of the mentioned
Answer
Answer: a [Reason:] None.
3. The FAT is used much as a ___
a) stack
b) linked list
c) data
d) pointer
Answer
Answer: b [Reason:] None.
4. A section of disk at the beginning of each partition is set aside to contain the table in :
a) fat
b) linked allocation
c) hashed allocation
d) indexed allocation
Answer
Answer: a [Reason:] None.
5. Contiguous allocation has two problems ___ and ___ that linked allocation solves.
a) external – fragmentation & size – declaration
b) internal – fragmentation & external – fragmentation
c) size – declaration & internal – fragmentation
d) memory – allocation & size – declaration
Answer
Answer: a [Reason:] None.
6. Each _______ has its own index block.
a) partition
b) address
c) file
d) all of the mentioned
Answer
Answer: c [Reason:] None.
7. Indexed allocation ___ direct access.
a) supports
b) does not support
c) is not related to
d) none of the mentioned
Answer
Answer: a [Reason:] None.
8. The pointer overhead of indexed allocation is generally ___ the pointer overhead of linked allocation.
a) less than
b) equal to
c) greater than
d) keeps varying with
Answer
Answer: c [Reason:] None.
9. For any type of access, contiguous allocation requires ______ access to get a disk block.
a) only one
b) atleast two
c) exactly two
d) none of the mentioned
Answer
Answer: a [Reason:] We can easily keep the initial address of the file in memory and calculate immediately the disk address of the ith block and read it directly.
10. Consider a disk where blocks 2,3,4,5,8,9,10,11,12,13,17,18,25,26 and 27 are free and the rest of the blocks are allocated. Then the free space bit map would be :
a) 10000110000001110011111100011111…
b) 110000110000001110011111100011111…
c) 01111001111110001100000011100000…
d) 001111001111110001100000011100000…
Answer
Answer: d [Reason:] None.
