Loading....
|
Press & Hold to Drag Around |
|||
|
Click Here to Close |
|||
Question 1 Report
The diagram shows a temporary network used by researchers at four tents on a coastal survey. Each radio unit passes messages to the next unit around the route shown in Fig. 1. A message from tent P must reach tent S.
(a) State the name of this topology. [1]
(b) Give the route, using tent letters, that a message takes from P to S if it travels clockwise. [1]
(c) State two problems that could occur if radio unit Q fails and messages are only sent clockwise. [2]
Fig. 1 shows a client-server network in a dental clinic. Reception computers use the server to store appointment records. The server has more memory and processing power than the client computers.
(a) State the role of the server in this network. [1]
(b) Give one benefit of keeping appointment files on the server rather than separately on every client computer. [1]
(c) State two effects on staff if the server fails during the day. [2]
Coastal-survey network
(a) The topology is a ring topology. [1]
(b) Clockwise from P to S, the route is P → Q → R → S. [1]
(c) If Q fails and messages can travel only clockwise:
Communication is interrupted for devices that rely on that direction. Any two [2].
Dental-clinic client-server network
(a) The server provides shared services or stores shared data for the client computers, including appointment records. [1]
(b) Files are held centrally, so staff access the same current appointment record. Easier backups are also an acceptable benefit. [1]
(c) If the server fails, staff may be unable to access appointment records and unable to save new appointments centrally. Shared network services become unavailable. Any two [2].
Coastal-survey network
(a) The topology is a ring topology. [1]
(b) Clockwise from P to S, the route is P → Q → R → S. [1]
(c) If Q fails and messages can travel only clockwise:
Communication is interrupted for devices that rely on that direction. Any two [2].
Dental-clinic client-server network
(a) The server provides shared services or stores shared data for the client computers, including appointment records. [1]
(b) Files are held centrally, so staff access the same current appointment record. Easier backups are also an acceptable benefit. [1]
(c) If the server fails, staff may be unable to access appointment records and unable to save new appointments centrally. Shared network services become unavailable. Any two [2].
Question 2 Report
Fig. 1 shows part of the HTML file used by a coastal rescue group for its public computer network page. The programmer wants the browser to show a heading and a link to an emergency map. The text inside the tags is shown in the diagram.
(a) State the purpose of the <h1> element. [2]
(b) Give the filename of the web page that opens when a user selects the link. [2]
(a) The <h1> element creates a level 1 heading. [1] In this code, the heading text is “Rescue stations”. [1] It identifies the main heading of the page or section.
(b) Selecting the link opens map.html. [2] This is the filename given by the link’s href attribute.
(a) The <h1> element creates a level 1 heading. [1] In this code, the heading text is “Rescue stations”. [1] It identifies the main heading of the page or section.
(b) Selecting the link opens map.html. [2] This is the filename given by the link’s href attribute.
Question 3 Report
The navigation computer on a research boat receives position readings from a GPS receiver. It fetches an instruction from memory, decodes it, then executes it to update the displayed route. The next instruction address is held by the program counter.
(a) State what is meant by an instruction. [1]
(b) Give the role of the memory address register during the fetch stage. [2]
(c) State the role of the memory data register when an instruction is read from memory. [1]
(d) Give two reasons why the program counter must be updated during normal sequential execution. [2]
(a) An instruction is a command that tells the processor what operation to perform. [1 mark]
(b) During fetch, the memory address register holds the address to be accessed [1] and sends that address to memory via the address bus [1]. [2 marks]
(c) When an instruction is read from memory, the memory data register holds the instruction or data being transferred. [1 mark]
(d) The program counter is incremented [1] so it identifies the address of the following instruction [1]. This lets the CPU continue through instructions in normal sequential order. [2 marks]
(a) An instruction is a command that tells the processor what operation to perform. [1 mark]
(b) During fetch, the memory address register holds the address to be accessed [1] and sends that address to memory via the address bus [1]. [2 marks]
(c) When an instruction is read from memory, the memory data register holds the instruction or data being transferred. [1 mark]
(d) The program counter is incremented [1] so it identifies the address of the following instruction [1]. This lets the CPU continue through instructions in normal sequential order. [2 marks]
Question 4 Report
Fig. 1 shows a diagnostic display from a solar-power inverter. The display uses hexadecimal 00AF for an error counter. A technician converts the value before entering it into a decimal report. The first two digits are zero because the counter is stored in a 16-bit memory location.
(a) Give the decimal value of hexadecimal 00AF. [3]
(b) Give the 16-bit binary value of hexadecimal 00AF. [2]
(c) State why the two leading hexadecimal zeroes are retained on the display. [2]
(a) The leading zeroes have no value. \(A=10\) and \(F=15\): \[10\times16+15=160+15=\mathbf{175}\] [3]
(b) Convert each hexadecimal digit into four bits: \(0=0000\), \(0=0000\), \(A=1010\), \(F=1111\). Therefore the 16-bit value is 0000 0000 1010 1111. [2]
(c) The zeroes are retained to show that the value occupies a fixed four-hexadecimal-digit, 16-bit field. They do not alter the numerical value. [2]
(a) The leading zeroes have no value. \(A=10\) and \(F=15\): \[10\times16+15=160+15=\mathbf{175}\] [3]
(b) Convert each hexadecimal digit into four bits: \(0=0000\), \(0=0000\), \(A=1010\), \(F=1111\). Therefore the 16-bit value is 0000 0000 1010 1111. [2]
(c) The zeroes are retained to show that the value occupies a fixed four-hexadecimal-digit, 16-bit field. They do not alter the numerical value. [2]
Question 5 Report
A librarian is checking the reading-festival page shown in Fig. 1. The page uses a heading hierarchy so that a screen-reader user can move through the content. One heading has been given the wrong level. The title of the whole page is Reading Festival, while Author sessions and Poetry workshop are sections within it.
(a) State the heading tag that should be used for Reading Festival. [1]
(b) Give the tag that should replace the first tag in Fig. 1. [2]
(c) Explain why heading levels should not be chosen only to make text appear larger. [3]
(a) Reading Festival, the title of the whole page, should use <h1>. [1] The main page heading is level 1.
(b) The first heading should be written as <h1>Reading Festival</h1>. The opening <h1> earns [1] and the closing </h1> earns [1].
(c) Heading tags communicate document structure. [1] Screen readers use this hierarchy to navigate between sections. [1] Therefore levels should reflect the relationship between the page title and its sections, not visual size. Visual size should be controlled using CSS. [1]
(a) Reading Festival, the title of the whole page, should use <h1>. [1] The main page heading is level 1.
(b) The first heading should be written as <h1>Reading Festival</h1>. The opening <h1> earns [1] and the closing </h1> earns [1].
(c) Heading tags communicate document structure. [1] Screen readers use this hierarchy to navigate between sections. [1] Therefore levels should reflect the relationship between the page title and its sections, not visual size. Visual size should be controlled using CSS. [1]
Question 6 Report
A railway heritage group is adding a video to its web page. Fig. 1 shows the required player and the available media files. Visitors use different browsers, so the HTML must offer more than one video format and must show controls.
(a) State the HTML element used to embed the player. [1]
(b) Give the attribute that displays play and volume controls. [1]
(c) Give two source elements for the files shown. [4]
(d) Explain why two file formats are supplied. [2]
(a) The player is embedded with a <video> element. [1]
(b) The attribute is controls. [1] It displays built-in controls such as play and volume controls.
(c) The two source elements are:
<source src="steamtrain.mp4" type="video/mp4">
<source src="steamtrain.webm" type="video/webm">Each complete source element earns [2], including the correct file and MIME type.
(d) Browsers may not support the same video formats. [1] Providing an alternative format allows more visitors to play the video. [1]
(a) The player is embedded with a <video> element. [1]
(b) The attribute is controls. [1] It displays built-in controls such as play and volume controls.
(c) The two source elements are:
<source src="steamtrain.mp4" type="video/mp4">
<source src="steamtrain.webm" type="video/webm">Each complete source element earns [2], including the correct file and MIME type.
(d) Browsers may not support the same video formats. [1] Providing an alternative format allows more visitors to play the video. [1]
Question 7 Report
The emergency radio network records equipment inspections using Fig. 1. Each radio has a serial number. Inspectors complete several checks during one inspection, and the database must record the result of every check without repeating the inspection date for each item.
(a) State the relationship between Inspection and CheckResult. [1]
(b) Give two fields that could form a composite key in CheckResult. [2]
(c) State one field that should be stored in Inspection. [1]
(d) Give one advantage of this design over placing Check1, Check2 and Check3 in Inspection. [1]
(e) State a suitable data type for a pass or fail result. [1]
This design separates an inspection from its individual check results. It avoids storing a fixed set of repeating Check fields.
This design separates an inspection from its individual check results. It avoids storing a fixed set of repeating Check fields.
Question 8 Report
The concert-entry algorithm checks three Boolean values stored after a QR scan: ticketValid, bagChecked and staffPass. A visitor enters if the ticket is valid and the bag has been checked. A staff-pass holder enters without those two checks, unless the venue is locked down. The variable lockdown is true during an emergency.
(a) Give the Boolean expression for allowEntry. [4]
(b) State the output when ticketValid is true, bagChecked is false, staffPass is false and lockdown is false. [1]
(c) State the output when ticketValid is false, bagChecked is false, staffPass is true and lockdown is false. [1]
(d) State the output when ticketValid is true, bagChecked is true, staffPass is true and lockdown is true. [1]
(e) Give one security reason for applying NOT lockdown to the whole entry rule. [2]
There are two possible entry routes, valid ticket plus checked bag, or staff pass. Lockdown is a final safety restriction applied to both routes.
((ticketValid AND bagChecked) OR staffPass) AND NOT lockdown. [4]bagChecked is false, and there is no staff pass. The output is false. [1]NOT lockdown is false and the output is false. [1]NOT lockdown to the whole rule prevents every entry route during lockdown, including ticket holders and staff-pass holders. [2]There are two possible entry routes, valid ticket plus checked bag, or staff pass. Lockdown is a final safety restriction applied to both routes.
((ticketValid AND bagChecked) OR staffPass) AND NOT lockdown. [4]bagChecked is false, and there is no staff pass. The output is false. [1]NOT lockdown is false and the output is false. [1]NOT lockdown to the whole rule prevents every entry route during lockdown, including ticket holders and staff-pass holders. [2]Question 9 Report
Fig. 1 shows part of the route used by a robotics club to turn a program into instructions for a small computer. The club writes the source code in a language with English-like commands. The robot has limited memory and can only run binary machine-code instructions. The compiler is run before the robot is taken to a competition.
(a) State the classification of the language used to write the source code. [1]
(b) Give one reason why the robot cannot use the source code directly. [1]
(c) State what is produced by the compiler. [1]
(d) Give one advantage of using a compiler for this robot program. [1]
(a) The source language is a high-level language [1], as it uses English-like commands.
(b) The robot cannot use the source code directly because its processor understands only machine-code, binary instructions [1].
(c) The compiler produces object code, machine code, or executable code [1].
(d) A compiled robot program can run without the compiler being present [1]. It can also run faster than interpreted code, which is useful when the robot is away from the development computer.
(a) The source language is a high-level language [1], as it uses English-like commands.
(b) The robot cannot use the source code directly because its processor understands only machine-code, binary instructions [1].
(c) The compiler produces object code, machine code, or executable code [1].
(d) A compiled robot program can run without the compiler being present [1]. It can also run faster than interpreted code, which is useful when the robot is away from the development computer.
Would you like to proceed with this action?