650+ Operating System (OS) Solved MCQs

101.

Control Unit acts as the central nervous system of the computer.

A. true
B. false
Answer» A. true
102.

What does MBR stand for?

A. main buffer register
B. memory buffer routine
C. main buffer routine
D. memory buffer register
Answer» D. memory buffer register
103.

In the instruction ADD A, B, the answer gets stored in                        

A. b
B. a
C. buffer
D. c
Answer» B. a
104.

What does PC stand for?

A. program changer
B. program counter
C. performance counter
D. performance changer
Answer» B. program counter
105.

Which of the following holds the last instruction fetched?

A. pc
B. mar
C. mbr
D. ir
Answer» D. ir
106.

The portion of the processor which contains the hardware required to fetch the operations is                

A. datapath
B. processor
C. control
D. output unit
Answer» A. datapath
107.

Causing the CPU to step through a series of micro operations is called                    

A. execution
B. runtime
C. sequencing
D. pipelining
Answer» C. sequencing
108.

The functions of execution and sequencing are performed by using                              

A. input signals
B. output signals
C. control signals
D. cpu
Answer» C. control signals
109.

What does D in the D-flip flop stand for?

A. digital
B. direct
C. delay
D. durable
Answer» C. delay
110.

What is the high speed memory between the main memory and the CPU called?

A. register memory
B. cache memory
C. storage memory
D. virtual memory
Answer» B. cache memory
111.

Cache Memory is implemented using the DRAM chips.

A. true
B. false
Answer» B. false
112.

Whenever the data is found in the cache memory it is called as                    

A. hit
B. miss
C. found
D. error
Answer» A. hit
113.

LRU stands for                        

A. low rate usage
B. least rate usage
C. least recently used
D. low required usage
Answer» C. least recently used
114.

When the data at a location in cache is different from the data located in the main memory, the cache is called                            

A. unique
B. inconsistent
C. variable
D. fault
Answer» B. inconsistent
115.

Which of the following is not a write policy to avoid Cache Coherence?

A. write through
B. write within
C. write back
D. buffered write
Answer» B. write within
116.

Which of the following is an efficient method of cache updating?

A. snoopy writes
B. write through
C. write within
D. buffered write
Answer» A. snoopy writes
117.

In                          mapping, the data can be mapped anywhere in the Cache Memory.

A. associative
B. direct
C. set associative
D. indirect
Answer» A. associative
118.

The number of sign bits in a 32-bit IEEE format is          

A. 1
B. 11
C. 9
D. 23
Answer» A. 1
119.

The transfer between CPU and Cache is

A. block transfer
B. word transfer
C. set transfer
D. associative transfer
Answer» B. word transfer
120.

Computer has a built-in system clock that emits millions of regularly spaced electric pulses per            called clock cycles.

A. second
B. millisecond
C. microsecond
D. minute
Answer» A. second
121.

It takes one clock cycle to perform a basic operation.

A. true
B. false
Answer» A. true
122.

The operation that does not involves clock cycles is                    

A. installation of a device
B. execute
C. fetch
D. decode
Answer» A. installation of a device
123.

The number of clock cycles per second is referred as                  

A. clock speed
B. clock frequency
C. clock rate
D. clock timing
Answer» A. clock speed
124.

CISC stands for                          

A. complex information sensed cpu
B. complex instruction set computer
C. complex intelligence sensed cpu
D. complex instruction set cpu
Answer» B. complex instruction set computer
125.

Which of the following processor has a fixed length of instructions?

A. cisc
B. risc
C. epic
D. multi-core
Answer» B. risc
126.

Processor which is complex and expensive to produce is                  

A. risc
B. epic
C. cisc
D. multi-core
Answer» C. cisc
127.

The architecture that uses a tighter coupling between the compiler and the processor is                          

A. epic
B. multi-core
C. risc
D. cisc
Answer» A. epic
128.

MAR stands for                        

A. memory address register
B. main address register
C. main accessible register
D. memory accessible register
Answer» A. memory address register
129.

A circuitry that processes that responds to and processes the basic instructions that are required to drive a computer system is

A. memory
B. alu
C. cu
D. processor
Answer» D. processor
130.

Any electronic holding place where data can be stored and retrieved later whenever required is                          

A. memory
B. drive
C. disk
D. circuit
Answer» A. memory
131.

Cache memory is the onboard storage.

A. true
B. false
Answer» A. true
132.

Which of the following is the fastest means of memory access for CPU?

A. registers
B. cache
C. main memory
D. virtual memory
Answer» A. registers
133.

The memory implemented using the semiconductor chips is                    

A. cache
B. main
C. secondary
D. registers
Answer» B. main
134.

Size of the                  memory mainly depends on the size of the address bus.

A. main
B. virtual
C. secondary
D. cache
Answer» A. main
135.

Which of the following is independent of the address bus?

A. secondary memory
B. main memory
C. onboard memory
D. cache memory
Answer» A. secondary memory
136.

                         storage is a system where a robotic arm will connect or disconnect off- line mass storage media according to the computer operating system demands.

A. secondary
B. virtual
C. tertiary
D. magnetic
Answer» C. tertiary
137.

What is the location of the internal registers of CPU?

A. internal
B. on-chip
C. external
D. motherboard
Answer» B. on-chip
138.

If M denotes the number of memory locations and N denotes the word size, then an expression that denotes the storage capacity is                              

A. m*n
B. m+n
C. 2m+n
D. 2m-n
Answer» A. m*n
139.

The operation that does not involves clock cycles is                          

A. installation of a device
B. execute
C. fetch
D. decode
Answer» A. installation of a device
140.

The number of clock cycles per second is referred as              

A. clock speed
B. clock frequency
C. clock rate
D. clock timing
Answer» A. clock speed
141.

CISC stands for                        

A. complex information sensed cpu
B. complex instruction set computer
C. complex intelligence sensed cpu
D. complex instruction set cpu
Answer» B. complex instruction set computer
142.

Processor which is complex and expensive to produce                    

A. risc
B. epic
C. cisc
D. multi-core
Answer» C. cisc
143.

The architecture that uses a tighter coupling between the compiler and the processor.

A. epic
B. multi-core
C. risc
D. cisc
Answer» A. epic
144.

HLDA stands for                

A. high level data
B. high level data acknowledgment
C. hold acknowledgement
D. hold data
Answer» C. hold acknowledgement
145.

Word length of a personal computer

A. 64bits
B. 16 bits
C. 8 bits
D. 32 bits
Answer» C. 8 bits
146.

Winchester disks are a type of                

A. optical disks
B. magnetic disks
C. compact disks
D. magnetic drives
Answer» B. magnetic disks
147.

Bernoulli disks are a type of magnetic floppy disks.

A. true
B. false
Answer» B. false
148.

A plug and play storage device that simply plugs in the port of a computer is                      

A. flash drive
B. compact disk
C. hard disk
D. cd
Answer» A. flash drive
149.

What does USB stand for?

A. universal signal board
B. universal signal bus
C. universal serial bus
D. universal serial board
Answer» C. universal serial bus
150.

A device similar to a flash drive

A. memory card
B. compact drive
C. compact disk
D. memory disk
Answer» A. memory card
151.

What does RAID stand for?

A. redundant array of independent disks
B. redundant array of inexpensive disks
C. redundant array of intermediate disks
D. redundant array of improper disks
Answer» A. redundant array of independent disks
152.

A set of hard disk drives with a controller mounted in a single box, forming a single large storage unit is                          

A. disk array
B. drives
C. compact drives
D. multi-cores
Answer» A. disk array
153.

The process in which a file is partitioned into smaller parts and different parts are stored in different disks is                          

A. raid
B. mirroring
C. stripping
D. raid classification
Answer» C. stripping
154.

Which of the following uses multiple hard disk platters mounted on a single central shift?

A. disk drives
B. hard disks
C. disk packs
D. compact disks
Answer» C. disk packs
155.

Which of the following is not a magnetic disk?

A. floppy
B. winchester
C. zip
D. flash
Answer» D. flash
156.

The software substituted for hardware and stored in ROM.

A. synchronous software
B. package software
C. firmware
D. middleware
Answer» C. firmware
157.

Middleware has enabled the production of various types of smart machines having microprocessor chips with embedded software.

A. true
B. false
Answer» B. false
158.

A “glue” between client and server parts of application.

A. middleware
B. firmware
C. package
D. system software
Answer» A. middleware
159.

MOM stands for?

A. message oriented middleware
B. mails oriented middleware
C. middleware of messages
D. main object middleware
Answer» A. message oriented middleware
160.

Storage of firmware is                        

A. cache memory
B. ram
C. external
D. rom
Answer» D. rom
161.

DNS stands for?

A. domain name system
B. direct name system
C. direct network system
D. domain network system
Answer» A. domain name system
162.

A software that lies between the OS and the applications running on it.

A. firmware
B. middleware
C. utility software
D. application software
Answer» B. middleware
163.

A type of middleware that allows for between the built-in applications and the real- time OS?

A. firmware
B. database middleware
C. portals
D. embedded middleware
Answer» D. embedded middleware
164.

What is the other name for object middleware?

A. object request interface
B. object enabled interface
C. object request broker
D. object enabled broker
Answer» C. object request broker
165.

The                calls certain procedures on remote systems and is used to perform synchronous or asynchronous interactions between systems.

A. procedure
B. rpc
C. message oriented
D. db
Answer» B. rpc
166.

Which module gives control of the CPU to the process selected by the short-term scheduler?

A. dispatcher
B. interrupt
C. scheduler
D. none of the mentioned
Answer» A. dispatcher
167.

In priority scheduling algorithm

A. cpu is allocated to the process with highest priority
B. cpu is allocated to the process with lowest priority
C. equal priority processes can not be scheduled
D. none of the mentioned
Answer» A. cpu is allocated to the process with highest priority
168.

The interval from the time of submission of a process to the time of completion is termed as                          

A. waiting time
B. turnaround time
C. response time
D. throughput
Answer» B. turnaround time
169.

Which scheduling algorithm allocates the CPU first to the process that requests the CPU first?

A. first-come, first-served scheduling
B. shortest job scheduling
C. priority scheduling
D. none of the mentioned
Answer» A. first-come, first-served scheduling
170.

Which algorithm is defined in Time quantum?

A. shortest job scheduling algorithm
B. round robin scheduling algorithm
C. priority scheduling algorithm
D. multilevel queue scheduling algorithm
Answer» B. round robin scheduling algorithm
171.

Process are classified into different groups in                          

A. shortest job scheduling algorithm
B. round robin scheduling algorithm
C. priority scheduling algorithm
D. multilevel queue scheduling algorithm
Answer» D. multilevel queue scheduling algorithm
172.

Which one of the following can not be scheduled by the kernel?

A. kernel level thread
B. user level thread
C. process
D. none of the mentioned
Answer» B. user level thread
173.

CPU scheduling is the basis of

A. multiprocessor systems
B. multiprogramming operating systems
C. larger memory sized systems
D. none of the mentioned
Answer» B. multiprogramming operating systems
174.

With multiprogramming              is used productively.

A. time
B. space
C. money
D. all of the mentioned
Answer» A. time
175.

What are the two steps of a process execution?

A. i/o & os burst
B. cpu & i/o burst
C. memory & i/o burst
D. os & memory burst
Answer» B. cpu & i/o burst
176.

An I/O bound program will typically have

A. a few very short cpu bursts
B. many very short i/o bursts
C. many very short cpu bursts
D. a few very short i/o bursts
Answer» C. many very short cpu bursts
177.

A process is selected from the               queue by the                  scheduler, to be executed.

A. blocked, short term
B. wait, long term
C. ready, short term
D. ready, long term
Answer» C. ready, short term
178.

In the following cases non – preemptive scheduling occurs?

A. when a process switches from the running state to the ready state
B. when a process goes from the running state to the waiting state
C. when a process switches from the waiting state to the ready state
D. all of the mentioned
Answer» B. when a process goes from the running state to the waiting state
179.

The switching of the CPU from one process or thread to another is called

A. process switch
B. task switch
C. context switch
D. all of the mentioned
Answer» D. all of the mentioned
180.

What is Dispatch latency?

A. the speed of dispatching a process from running to the ready state
B. the time of dispatching a process from running to ready state and keeping the cpu idle
C. the time to stop one process and start running another one
D. none of the mentioned
Answer» C. the time to stop one process and start running another one
181.

Scheduling is done so as to                          

A. increase cpu utilization
B. decrease cpu utilization
C. keep the cpu more idle
D. none of the mentioned
Answer» A. increase cpu utilization
182.

Scheduling is done so as to

A. increase the throughput
B. decrease the throughput
C. increase the duration of a specific amount of work
D. none of the mentioned
Answer» A. increase the throughput
183.

What is Turnaround time?

A. the total waiting time for a process to finish execution
B. the total time spent in the ready queue
C. the total time spent in the running queue
D. the total time from the completion till the submission of a process
Answer» D. the total time from the completion till the submission of a process
184.

Scheduling is done so as to

A. increase the turnaround time
B. decrease the turnaround time
C. keep the turnaround time same
D. there is no relation between scheduling and turnaround time
Answer» B. decrease the turnaround time
185.

What is Waiting time?

A. the total time in the blocked and waiting queues
B. the total time spent in the ready queue
C. the total time spent in the running queue
D. the total time from the completion till the submission of a process
Answer» B. the total time spent in the ready queue
186.

Scheduling is done so as to

A. increase the waiting time
B. keep the waiting time the same
C. decrease the waiting time
D. none of the mentioned
Answer» C. decrease the waiting time
187.

What is Response time?

A. the total time taken from the submission time till the completion time
B. the total time taken from the submission time till the first response is produced
C. the total time taken from submission time till the response is output
D. none of the mentioned
Answer» B. the total time taken from the submission time till the first response is produced
188.

Round robin scheduling falls under the category of                          

A. non-preemptive scheduling
B. preemptive scheduling
C. all of the mentioned
D. none of the mentioned
Answer» B. preemptive scheduling
189.

With round robin scheduling algorithm in a time shared system                          

A. using very large time slices converts it into first come first served scheduling algorithm
B. using very small time slices converts it into first come first served scheduling algorithm
C. using extremely small time slices increases performance
D. using very small time slices converts it into shortest job first algorithm
Answer» A. using very large time slices converts it into first come first served scheduling algorithm
190.

The portion of the process scheduler in an operating system that dispatches processes is concerned with                          

A. assigning ready processes to cpu
B. assigning ready processes to waiting queue
C. assigning running processes to blocked queue
D. all of the mentioned
Answer» A. assigning ready processes to cpu
191.

Complex scheduling algorithms

A. are very appropriate for very large computers
B. use minimal resources
C. use many resources
D. all of the mentioned
Answer» A. are very appropriate for very large computers
192.

What is FIFO algorithm?

A. first executes the job that came in last in the queue
B. first executes the job that came in first in the queue
C. first executes the job that needs minimal processor
D. first executes the job that has maximum processor needs
Answer» B. first executes the job that came in first in the queue
193.

The strategy of making processes that are logically runnable to be temporarily suspended is called                          

A. non preemptive scheduling
B. preemptive scheduling
C. shortest job first
D. first come first served
Answer» B. preemptive scheduling
194.

What is Scheduling?

A. allowing a job to use the processor
B. making proper use of processor
C. all of the mentioned
D. none of the mentioned
Answer» A. allowing a job to use the processor
195.

There are 10 different processes running on a workstation. Idle processes are waiting for an input event in the input queue. Busy processes are scheduled with the Round- Robin time sharing method. Which out of the following quantum times is the best value for small response times, if the processes have a short runtime, e.g. less than 10ms?

A. tq = 15ms
B. tq = 40ms
C. tq = 45ms
D. tq = 50ms
Answer» A. tq = 15ms
196.

Orders are processed in the sequence they arrive if                rule sequences the jobs.

A. earliest due date
B. slack time remaining
C. first come, first served
D. critical ratio
Answer» C. first come, first served
197.

Which of the following algorithms tends to minimize the process flow time?

A. first come first served
B. shortest job first
C. earliest deadline first
D. longest job first
Answer» B. shortest job first
198.

Under multiprogramming, turnaround time for short jobs is usually                  and that for long jobs is slightly                        

A. lengthened; shortened
B. shortened; lengthened
C. shortened; shortened
D. shortened; unchanged
Answer» B. shortened; lengthened
199.

Which is the most optimal scheduling algorithm?

A. fcfs – first come first served
B. sjf – shortest job first
C. rr – round robin
D. none of the mentioned
Answer» B. sjf – shortest job first
200.

The real difficulty with SJF in short term scheduling is                          

A. it is too good an algorithm
B. knowing the length of the next cpu request
C. it is too complex to understand
D. none of the mentioned
Answer» B. knowing the length of the next cpu request
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