Network Topologies
12 Grade 10 Computer Studies questions on Network Topologies, with worked marking schemes. 12 questions are available on this topic in full.
Question 1
1 markWhy is a terminator fitted at each end of the backbone cable of a bus network?
A. To issue each computer on the backbone with its network address.
B. To supply electrical power to the computers attached to the backbone.
C. To absorb the signal when it reaches the end of the cable so that it does not bounce back and interfere with later transmissions.
D. To increase the speed at which the backbone carries data.
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 2
1 markA school computer laboratory is wired so that every computer has its own cable running to one central switch. One morning the central switch fails. What is the most likely effect on the laboratory?
A. Half the computers stay connected while the other half are cut off.
B. Every computer loses network access, although each machine still works on its own.
C. The network keeps running because data simply passes from one computer to the next.
D. Only the computers joined by the longest cables lose their connection.
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 3
1 markA government office wants a small network in which any two computers can still exchange data even after two or three individual links have failed. Which topology best meets this requirement?
A. Simple (single) ring topology
B. Star topology
C. Bus topology
D. Mesh topology
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 4
1 markA school is wiring twenty computers. A star network of these twenty computers usually needs a greater total length of cable than a bus network of the same twenty computers. What is the reason for this?
A. A star network must include a spare cable to each computer for use when the first one fails.
B. Every computer on a star network needs two cables, one for sending and one for receiving.
C. The cables of a star network must be laid right round the walls of the room so that they form a closed loop.
D. Each computer needs its own separate cable running back to the central switch, while on a bus the computers share one backbone cable.
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 5
2 marksDistinguish between the physical topology and the logical topology of a network.
(2 marks)
Marking scheme for this question
Create a free account to see itQuestion 6
4 marksExplain why a bus topology would be unsuitable for a busy county office with thirty computers.
(4 marks)
Marking scheme
Award 1 mark for each valid reason explained, to a maximum of 4 marks. 1. All thirty machines share one backbone cable, so as traffic grows collisions increase and the network slows down. 2. A single break or loose connector on the backbone brings down the whole network, not just one user. 3. Faults are difficult to trace because the whole cable run must be tested to find the break. 4. The backbone has a limited length and a limited number of nodes it can support, so thirty machines may exceed it. 5. Adding a new computer means interrupting the backbone, which disrupts everyone working at the time. (Accept any four distinct reasons.)
Question 7
4 marksState four advantages of using a star topology to network the computers in a school laboratory.
(4 marks)
Marking scheme
Award 1 mark for each of any four correct advantages, to a maximum of 4 marks. 1. Failure of one computer or one cable affects only that machine; the rest of the network keeps working. 2. Faults are easy to locate and isolate because each computer has its own separate cable to the central device. 3. A new computer can be added or an old one removed without disturbing the other users. 4. Each machine has its own link to the switch, so performance is better than on a single shared cable. 5. The central device gives one convenient point for managing and monitoring the network. (Accept any four; do not credit the same point expressed twice.)
Question 8
1 markA matatu sacco office is networked using a single backbone cable to which all the computers are attached. A workman accidentally cuts the backbone halfway along its length. Which statement best describes what happens?
A. Data continues to flow normally but at half the usual speed.
B. Only the computer nearest the cut loses its connection.
C. Communication across the whole network fails because there is only one shared path for all the data.
D. The signal automatically takes another route around the cable and nothing is noticed.
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 9
3 marksIn a mesh topology every computer has a direct link to every other computer.
(a) State the number of cables needed to connect five computers in a full mesh.
(b) Give two reasons why a mesh topology is rarely used to wire a school computer laboratory.
(3 marks)
Marking scheme for this question
Create a free account to see itQuestion 10
1 markIn a simple ring topology, how does a message sent by one computer reach the computer it is addressed to?
A. It is first sent to a file server, which then forwards it to the destination.
B. It travels along a separate dedicated cable that joins the two computers directly.
C. It is broadcast to all the computers at the same time through a central hub.
D. It is passed from one computer to the next around the ring until it reaches the destination.
(1 mark)
Marking scheme for this question
Create a free account to see itQuestion 11
3 marksDescribe how data travels in a simple ring topology, and state one effect of a single computer in the ring breaking down.
(3 marks)
Marking scheme for this question
Create a free account to see itQuestion 12
3 marksA county agricultural training centre has an office block, a library and a workshop, each about sixty metres apart, and each containing about fifteen computers. Suggest a suitable network topology for the centre and justify your choice.
(3 marks)
Marking scheme
1. Suggestion: a tree (hierarchical) or star-based hybrid topology - a switch in each block, with all three switches linked to a main switch in the office block. (1 mark) 2. Justification: each block is wired as a star, so a fault in one block or on one cable affects only that block and the other two continue working. (1 mark) 3. Justification: the arrangement suits buildings that are far apart, keeps individual cable runs short, and allows a whole new block to be added later by linking one more switch to the main switch. (1 mark) Accept any sensible topology that is properly justified; the marks are for the justification, not the label alone.
9 more marking schemes are on this page. A free account opens all of them, and lets you build your own paper on the topics you have actually taught, laid out in KNEC format with its full marking scheme.
Create a free account