Answer:
The comparison is based on memory organization schemes of contiguous memory allocation and paging with respect to External fragmentation, Internal fragmentation and Ability to share code across processes.
Explanation:
Memory organization schemes of contiguous memory allocation:
Contiguous memory allocation schemes suffers from external fragmentation. The reason is that address space is distributed contiguously and the holes and gaps keep growing when the old processes die and new processes are introduced. The variable size partition suffers from external fragmentation however the fixed size partitions do not suffer from external fragmentation. Contiguous memory allocation with variable size partitions does not encounter an internal fragmentation but with fixed size partitions suffers from internal fragmentation. Contiguous memory allocation does not support sharing code across processes. This is because the virtual memory segment of a process is not fragmented into non-contiguous fine grained blocks.
Paging:
Paging does not encounter external fragmentation as pages are of the fixed or equal size. So this reduces external fragmentation. However paging suffers from internal fragmentation. This is because a process can request more space or it can request for a less space. When page is allocated to the such a process that page is no longer utilized.This results in internal fragmentation because of the wastage of space even when the page has internal space but cannot be fully utilized. Paging allows to share code across processes.
Answer: e) only A and B are correct
Explanation: Google + is a service that is used for social networking. It is like the other social networking devices work and provides similar services like searching, connecting people etc. This service was not successful approach among the users.Thus it was shut down at the certain point of time.
It had the mechanism in which the circles was used got the targeting and used for connecting account with other Google services.It also had the feature introduced named hashtag searches for searching but then discontinued this feature.So, only statement(a) and (b)are correct.Thus option(e) is the correct option.
Answer: Hub
Explanation:
Hub is a electronic and networking device that is placed in a network to maintain a common link with the multiple attached devices. Hub is situated at the physical layer of the Open systems interconnection(OSI) model.
- Hub is used for creation of link between numerous local area network sections as it persist various ports which replicates data packet and distributes to other ports.
- There are different types of hub for different purpose of connection such as USB hub, Ethernet hub etc.
