Operating System (OS)
The term 'polling' in a computer means a process by which a computer system

inquires to see if a terminal has any transaction to send
detects/corrects errors
multiplexes the inputs and updates the memory accordingly
None of these
decides correct alternative by analysing several ones

ANSWER DOWNLOAD EXAMIANS APP

Operating System (OS)
System maintenance:

is usually not necessary
is not required if the system is well written
always requires several programs
None of these
is necessary on all systems, regardless of how good

ANSWER DOWNLOAD EXAMIANS APP

Operating System (OS)
Semaphores

synchronize critical resources to prevent contention
synchronize critical resources to prevent deadlock
None of these
are used to do I/O
are used for memory management

ANSWER DOWNLOAD EXAMIANS APP