21)In which one of the following page replacement policies, Belady’s anomaly may occur?
(A) FIFO
(B) Optimal
(C) LRU
(D) MRU
22) What is operating system?
a)collection of programs that manages hardware resources
b)system service provider to the application programs
c)link to interface the hardware and application programs
d)all of the mentioned
23)A process can be terminated due to
a) normal exit
b)fatal error
c)killed by another process
d)all of the mentioned
24) If a process fails, most operating system write the error information to a
a)log file
b) another running process
c) new file
d) none of the mentioned
25) To avoid the race condition, the number of processes that may be simultaneously inside their critical section is
a)1
b)3
c)5
d)7
26)What should be the size of ROM if it is used to store the table for multiplication of two 8 – bit unsigned integers?
a) 64k x 8
b) 64k x 16
c) 4k x 8
d) 64k x 16
27)What must reside in the main memory under all situations in a resident – OS computer?
a) Linker
b) Loader
c) Assembler
d) Compiler
28)In a virtual memory environment the minimum number of page frames that must be allocated to a running process is determined by ___________________.
a) The Number of Processes in the Memory
b) The Instruction Set Architecture
c) The Page Size
d) The Physical Memory Size
29) A machine has a physical memory of 64 Mbyte and a virtual address space of 32 – bit. The page size is 4kbyte, What is the approximate size of the page table?
a) 24 Mbyte
b) 16 Mbyte
c) 2 Mbyte
d) 8 Mbyte
30)What invokes the system calls?
a) A privileged instruction
b) An indirect jump
c) A software interrupt
d) Polling