In a two -level virtual memory, the memory access time for main memory, $${t_M} = {10^{ - 8}}\sec $$ and the memory access time for the secondary memory, tag $$ = {10^{ - 3}}.$$ What must be the hit ratio, $$H$$ such that the access efficiency is within $$80$$ percent of its maximum value?

Under paged memory management scheme simple lock and key memory protection arrangement may still be required if the $$........$$ processors do not have address mapping hardware.

Match the pairs in the following Question.
$$\eqalign{ & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,List:\,{\rm I} \cr & \left( A \right)\,\,Criotical\,\,region \cr & \left( B \right)\,\,Wait/Signal \cr & \left( C \right)\,\,Working\,\,set \cr & \left( D \right)\,\,Deadlock \cr & \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,List:\,{\rm I}{\rm I} \cr & \left( p \right)\,\,Hoare's\,\,monitor \cr & \left( q \right)\,\,Mutual\,\,exclusion \cr & \left( r \right)\,\,\Pr inciple\,\,of\,\,locality \cr & \left( s \right)\,\,Circular\,\,Wait \cr} $$

Match the pairs in the following question.

List - $${\rm I}$$
$$(A)$$$$\,\,\,\,$$ Virtual Memory
$$(B)$$$$\,\,\,\,$$ Shared memory
$$(C)$$$$\,\,\,\,$$ Look-ahead buffer
$$(D)$$$$\,\,\,\,$$ Look-aside buffer

List - $${\rm II}$$
$$(p)$$$$\,\,\,\,$$ Temporal locality
$$(q)$$$$\,\,\,\,$$ Spatial Locality
$$(r)$$$$\,\,\,\,$$ Address Translation
$$(s)$$$$\,\,\,\,$$ Mutual exclusion