Time allowed: 1 hour 30 minutes
A desktop computer uses a Von Neumann architecture CPU.
(a) State the purpose of the Control Unit (CU).
(b) Describe the role of the following registers during the fetch-execute cycle:
(i) Memory Address Register (MAR)
(ii) Memory Data Register (MDR)
(c) Describe the stages of the fetch-execute cycle.
A smart-city traffic management system uses embedded controllers to manage the signals at a busy junction.
(a) State two characteristics of an embedded system.
1.
2.
(b) Justify the use of an embedded system for the traffic light signals rather than using a general-purpose computer.
A computer uses both RAM and ROM for primary storage.
(a) State two technical differences between RAM and ROM. For each difference, refer to both RAM and ROM.
Difference 1:
Difference 2:
(b) When the RAM is full, the operating system may use Virtual Memory.
Explain how Virtual Memory is used to allow more programs to run.
A plain text document contains 12,000 characters. Each character is stored using the 8-bit extended ASCII character set.
(a) Calculate the file size of the document in Kilobytes (KB). Show your working.
Working:
Answer: KB
(b) Tick (✓) one box on each row to identify the correct equivalent for each value.
| Value | 3,000 MB | 3,000 GB | 30 KB | 3,000,000 Bytes |
|---|---|---|---|---|
| 3 Gigabytes (GB) | ||||
| 3 Terabytes (TB) | ||||
| 3 Megabytes (MB) | ||||
| 30,000 Bytes |
A police officer uses a wearable body-camera to record footage while on patrol. The device uses Solid State storage.
(a) Justify the choice of Solid State storage rather than Magnetic storage for this wearable device.
(b) State one characteristic of secondary storage, other than speed or portability, that is important in this scenario. Give one reason for your choice.
Characteristic:
Reason:
Eco-Clean is a company that uses automated drones to monitor pollution levels in rivers. The drones use sensors to collect data and transmit it wirelessly to a central server.
(a) The drones connect to the server via a wireless network.
Explain how bandwidth and latency can affect the performance of the drone's data transmission.
Bandwidth:
Latency:
(b) Identify two hardware components required by the drone to connect to the wireless network.
1.
2.
(a) Each drone is identified on the network by both an IP address and a MAC address.
Describe two differences between an IP address and a MAC address.
Difference 1:
Difference 2:
(b) The drone uses a Domain Name Server (DNS) to find the IP address of the company's web server.
Order the following steps (1-4) to show how a DNS lookup is performed.
| Action | Order (1-4) |
|---|---|
| The IP address is returned to the drone. | |
| The URL is sent to a Domain Name Server. | |
| The drone sends a request to the web server using the IP address. | |
| The DNS server looks up the domain name in its database. |
(a) The drone transmits its findings securely using various protocols.
Identify which protocol is most suitable for each task described in the table below.
| Task | Protocol |
|---|---|
| Uploading large raw pollution data files to the central server. | |
| Accessing the company's secure monitoring website. | |
| Sending automated status reports to the manager via email. |
(b) The company uses layers to manage their network protocols.
State one benefit of using layers in a network model.
Eco-Clean is concerned about the security of their data.
(a) Explain how data interception can be used to compromise the security of Eco-Clean's network.
(b) Define the network security threat known as SQL Injection.
Eco-Clean employs a security consultant to perform a penetration test on their network.
Explain the purpose of penetration testing and how it is applied to improve network security.
The central server uses an operating system to manage its resources.
(a) The drones use various sensors that require specialised software to communicate with the operating system.
Describe the role of a device driver in this process.
(b) Identify three functions of an operating system, other than peripheral management.
1.
2.
3.
Eco-Clean's automated drones monitor pollution levels in rivers, but their high-definition cameras also capture footage of members of the public using the riverbanks without their explicit consent.
Discuss the impacts of Eco-Clean's drone technology. Your answer should consider: