Operating System MCQ (Multiple Choice Questions) - SchoolingAxis

Operating System MCQ (Multiple Choice Questions)

 Que- The ___________ swaps processes in and out of the memory. 

a. Memory manager 

b. CPU 

c. CPU manager 

d. User 


Answer- Memory manager        


Que- If a higher priority process arrives and wants service, the memory manager can swap out the lower priority process to execute the higher priority process. When the higher priority process finishes, the lower priority process is swapped back in and continues execution. This variant of swapping is sometimes called : 

a. priority swapping 

b. pull out, push in 

c. roll out, roll in 

d. none of the mentioned 


Answer- roll out, roll in        


Que- If binding is done at assembly or load time, then the process _____ be moved to different locations after being swapped out and in again. 

a. can 

b. must 

c. can never 

d. may 


Answer- can never        


Que- In a system that does not support swapping, 

a. the compiler normally binds symbolic addresses (variables) to relocatable addresses 

b. the compiler normally binds symbolic addresses to physical addresses 

c. the loader binds relocatable addresses to physical addresses 

d. binding of symbolic addresses to physical addresses normally takes place during execution 


Answer- the compiler normally binds symbolic addresses (variables) to relocatable addresses        


Que- Which of the following is TRUE ? 

a. Overlays are used to increase the size of physical memory 

b. Overlays are used to increase the logical address space 

c. When overlays are used, the size of a process is not limited to the size of the physical memory 

d. Overlays are used whenever the physical address space is smaller than the logical address space 


Answer- When overlays are used, the size of a process is not limited to the size of the physical memory        


Que- The address generated by the CPU is referred to as : 

a. Physical address 

b. Logical address 

c. Neither physical nor logical 

d. None of the mentioned 


Answer- Logical address        


Que- The address loaded into the memory address register of the memory is referred to as : 

a. Physical address 

b. Logical address 

c. Neither physical nor logical 

d. None of the mentioned 


Answer- Physical address        


Que- The run time mapping from virtual to physical addresses is done by a hardware device called the : 

a. Virtual to physical mapper 

b. Memory management unit 

c. Memory mapping unit 

d. None of the mentioned 


Answer- Memory management unit        


Que- The base register is also known as the : 

a. basic register 

b. regular register 

c. relocation register 

d. delocation register 


Answer- relocation register        


Que- The size of a process is limited to the size of : 

a. physical memory 

b. external storage 

c. secondary storage 

d. none of the mentioned 


Answer- physical memory        


Que- If execution time binding is being used, then a process ______ be swapped to a different memory space. 

a. has to be 

b. can never 

c. must 

d. may 


Answer- may        


Que- Swapping requires a _________ 

a. motherboard 

b. keyboard 

c. monitor 

d. backing store 


Answer- backing store        


Que- The backing store is generally a : 

a. fast disk 

b. disk large enough to accommodate copies of all memory images for all users 

c. disk to provide direct access to the memory images 

d. all of the mentioned 


Answer- all of the mentioned        


Que- The ________ consists of all processes whose memory images are in the backing store or in memory and are ready to run. 

a. wait queue 

b. ready queue 

c. cpu 

d. secondary storage 


Answer- ready queue        


Que- The _________ time in a swap out of a running process and swap in of a new process into the memory is very high. 

a. context - switch 

b. waiting 

c. execution 

d. all of the mentioned 


Answer- context - switch        


Que- The major part of swap time is _______ time. 

a. waiting 

b. transfer 

c. execution 

d. none of the mentioned 


Answer- transfer        


Que- Swapping _______ be done when a process has pending I/O, or has to execute I/O operations only into operating system buffers. 

a. must 

b. can 

c. must never 

d. maybe 


Answer- must never        


Que- Swap space is allocated : 

a. as a chunk of disk 

b. separate from a file system 

c. into a file system 

d. all of the mentioned 


Answer- as a chunk of disk        


Que- CPU fetches the instruction from memory according to the value of 

a. program counter 

b. status register 

c. instruction register 

d. program status word  


Answer- program counter        


Que- A memory buffer used to accommodate a speed differential is called 

a. stack pointer 

b. cache 

c. accumulator 

d. disk buffer  


Answer- cache        


Que- Which one of the following is the address generated by CPU? 

a. physical address 

b. absolute address 

c. logical address 

d. none of the mentioned  


Answer- logical address        


Que- Run time mapping from virtual to physical address is done by 

a. Memory management unit 

b. CPU 

c. PCI 

d. None of the mentioned  


Answer- Memory management unit        


Que- Memory management technique in which system stores and retrieves data from secondary storage for use in main memory is called 

a. fragmentation 

b. paging 

c. mapping 

d. none of the mentioned  


Answer- paging        


Que- The address of a page table in memory is pointed by 

a. stack pointer 

b. page table base register 

c. page register 

d. program counter  


Answer- page table base register        


Que- Program always deals with 

a. logical address 

b. absolute address 

c. physical address 

d. relative address  


Answer- logical address        


Que- The page table contains 

a. base address of each page in physical memory 

b. page offset 

c. page size 

d. none of the mentioned  


Answer- base address of each page in physical memory        


Que- What is compaction? 

a. a technique for overcoming internal fragmentation 

b. a paging technique 

c. a technique for overcoming external fragmentation 

d. a technique for overcoming fatal error  


Answer- a technique for overcoming external fragmentation        


Que- Operating System maintains the page table for 

a. each process 

b. each thread 

c. each instruction 

d. each address  


Answer- each process        


Que- The main memory accommodates : 

a. operating system 

b. cpu 

c. user processes 

d. all of the mentioned 


Answer- operating system        


Que- The operating system is : 

a. in the low memory 

b. in the high memory 

c. either low or high memory (depending on the location of interrupt vector) 

d. none of the mentioned 


Answer- either low or high memory (depending on the location of interrupt vector)        


Que- In contiguous memory allocation : 

a. each process is contained in a single contiguous section of memory 

b. all processes are contained in a single contiguous section of memory 

c. the memory space is contiguous 

d. none of the mentioned 


Answer- each process is contained in a single contiguous section of memory        


Que- The relocation register helps in : 

a. providing more address space to processes 

b. a different address space to processes 

c. to protect the address spaces of processes 

d. none of the mentioned 


Answer- to protect the address spaces of processes        


Que- With relocation and limit registers, each logical address must be _______ the limit register. 

a. less than 

b. equal to 

c. greater than 

d. none of the mentioned 


Answer- less than        


Que- The operating system and the other processes are protected from being modified by an already running process because : 

a. they are in different memory spaces 

b. they are in different logical addresses 

c. they have a protection algorithm 

d. every address generated by the CPU is being checked against the relocation and limit registers 


Answer- every address generated by the CPU is being checked against the relocation and limit registers        


Que- Transient operating system code is code that : 

a. is not easily accessible 

b. comes and goes as needed 

c. stays in the memory always 

d. never enters the memory space 


Answer- comes and goes as needed        


Que- Using transient code, _______ the size of the operating system during program execution. 

a. increases 

b. decreases 

c. changes 

d. maintains 


Answer- changes        


Que- When memory is divided into several fixed sized partitions, each partition may contain ________ 

a. exactly one process 

b. at least one process 

c. multiple processes at once 

d. none of the mentioned 


Answer- exactly one process        


Que- In fixed size partition, the degree of multiprogramming is bounded by ___________ 

a. the number of partitions 

b. the CPU utilization 

c. the memory size 

d. all of the mentioned 


Answer- the number of partitions        


Que- The first fit, best fit and worst fit are strategies to select a ______ 

a. process from a queue to put in memory 

b. processor to run the next process 

c. free hole from a set of available holes 

d. all of the mentioned 


Answer- free hole from a set of available holes        


Que- In internal fragmentation, memory is internal to a partition and : 

a. is being used 

b. is not being used 

c. is always used 

d. none of the mentioned 


Answer- is not being used        


Que- A solution to the problem of external fragmentation is : 

a. compaction 

b. larger memory space 

c. smaller memory space 

d. none of the mentioned 


Answer- compaction        


Que- Another solution to the problem of external fragmentation problem is to : 

a. permit the logical address space of a process to be noncontiguous 

b. permit smaller processes to be allocated memory at last 

c. permit larger processes to be allocated memory at last 

d. all of the mentioned 


Answer- permit the logical address space of a process to be noncontiguous        


Que- If relocation is static and is done at assembly or load time, compaction _________ 

a. cannot be done 

b. must be done 

c. must not be done 

d. can be done 


Answer- cannot be done        


Que- The disadvantage of moving all process to one end of memory and all holes to the other direction, producing one large hole of available memory is : 

a. the cost incurred 

b. the memory used 

c. the CPU used 

d. all of the mentioned 


Answer- the cost incurred        


Que- __________ is generally faster than _________ and _________ 

a. first fit, best fit, worst fit 

b. best fit, first fit, worst fit 

c. worst fit, best fit, first fit 

d. none of the mentioned 


Answer- first fit, best fit, worst fit        


Que- External fragmentation exists when : 

a. enough total memory exists to satisfy a request but it is not contiguous 

b. the total memory is insufficient to satisfy a request 

c. a request cannot be satisfied even when the total memory is free 

d. none of the mentioned 


Answer- enough total memory exists to satisfy a request but it is not contiguous        


Que- External fragmentation will not occur when : 

a. first fit is used 

b. best fit is used 

c. worst fit is used 

d. no matter which algorithm is used, it will always occur 


Answer- no matter which algorithm is used, it will always occur        


Que- Sometimes the overhead of keeping track of a hole might be : 

a. larger than the memory 

b. larger than the hole itself 

c. very small 

d. all of the mentioned 


Answer- larger than the hole itself        


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