SQA H Computing SQP

Higher Computing

Specimen Paper

Not all questions have points but for those that do there are more points for quick answers and no points for wrong answers!

​Points make prizes

Multiple Choice

1. Convert the following 16-bit two’s complement number into denary. 1

1111 1110 1110 1011

• -436

• -277

• -183

• 56

Multiple Select

2. A developer and their client are based in different time zones in the world.

Explain the impact that this can have when using an agile methodology compared to an iterative one.

• One of them might be sleepy when they meet

• It is harder to manage the project when you cannot meet the client regularly

• The agile methodology requires more client interaction throughout the whole project, than the iterative one does.

• They are both the same

Multiple Select

3. A website is subject to a DOS attack.

State two symptoms users experience when this happens.

• Slow performance

• The site redirects to a false website

• All data becomes corrupted

• Inability to access data

4. A database table is shown below.

Draw

Complete the table below showing the output from the following SQL statement.

SELECT category, MAX(price) AS [Most expensive item] FROM Model

GROUP BY category;

Multiple Select

5. Describe one problem that can occur when using global variables in a program.

• Arrays will not work across the whole program.

• Accidental use of the same variable in different modules.

• It may be difficult for more than one programmer to work on the code.

• Nothing, its just to make programmers look smarter.

6. A text file stores the names of players and the time (in seconds) that they took to complete a game. Players who played the game more than once appear more than once in the file, as shown below.

…

Harry,1745

Gemma,1028

Jeremy,1209

Harry,1358

…

Open Ended

(a) Describe the purpose of the following steps in the algorithm.

(i) Steps 3 to 8

Open Ended

(a) Describe the purpose of the following steps in the algorithm.

(ii) Steps 9 to 16

Draw

8. Many sports clubs in Scotland have one president but they have many members. A member can only belong to one club.

Complete the entity-occurrence diagram below to represent the relationship between clubs, presidents and members.

Fill in the Blank

9. Convert 0·001011 to floating-point representation. There are 16 bits for the mantissa and 8 bits for the exponent.

Open Ended

11. Two computer systems have the same number of processor cores, the same width of data bus and the same clock speed.

(a) State one other factor that could account for one computer system performing better than the other, when tested for processing speed.

Open Ended

11. Two computer systems have the same number of processor cores, the same width of data bus and the same clock speed.

(b) Explain why increasing the width of the data bus will improve the system performance.

Open Ended

12. Describe the role of public and private keys when transferring secure data.

14. The International Bowling Federation maintains a relational database that consists of three linked tables, storing data on players, tournaments and tournament entries.

Extracts from these tables are shown below.

​

Open Ended

14. (a) Identify the compound key used in the Federation’s database.

Draw

14. Query 2 — Display largest amount of money when finishing first

Multiple Choice

14. (c) The Federation writes the following SQL statement to find how many times each country has awarded prizes of over 7000.

SELECT country, COUNT(prizeMoney)

FROM Tournament, Entry

WHERE prizeMoney > 7000

AND Tournament.tournamentID = Player.tournamentID

GROUP BY country;

(i) State the purpose of the GROUP BY line of the SQL statement.

• To create a link between the tables

• So that each country only appears once

• To sort the results alphabetically

• Because it does not work otherwise

Multiple Select

14. (c) (ii) The expected output of the SQL statement is shown.

When the SQL statement was tested, the actual output did not match the expected output.

Identify two errors in the SQL statement.

• The query should have been split into two seperate queries.

• The second half of JOIN should be = Entry.tournamentID

• (AS) [Over 7000] is missing from SQL

• SUM should have been used instead of COUNT

Multiple Choice

14(d) The Federation retains 10% of the total prize money.

Write the SQL statement that would produce the output shown.

• SELECT Count(prizemoney*10)

  AS [Retained prize money]

  FROM Entry;

• SELECT SUM(prizemoney*0.1)

  AS [Retained prize money]

  FROM Entry

  GROUP BY TournamentID;

• SELECT SUM(prizemoney*0.1)

  AS [Retained prize money]

  FROM Player;

• SELECT SUM(prizemoney*0.1)

  AS [Retained prize money]

  FROM Entry;

Draw

(e) Each player can only be a member of one bowling club.

Complete the entity-relationship diagram below to show how the club could be added to the database.

16. The Caesar cypher is a simple encryption method that takes each letter in a message and changes it to a different letter.

The program below asks the user to enter a message and an integer used to change the letters in the string.

Both inputs are passed to a function that generates and returns an encrypted version of the message.

​

Fill in the Blank

16. (a) The above code contains actual parameters and formal parameters. Identify an actual parameter in the code.

Draw

16. (b) A breakpoint is set at line 19.

The function is tested by entering the two inputs shown below.

Input 1: cab

Input 2: 3

Complete the table below to show the values of character and

newMessage each time execution is stopped.

Multiple Choice

16. (c) Using a programming language of your choice (VISUAL BASIC!), state the pre-defined function used to convert:

(i) Character to ASCII

• CHR

• MOD

• ASC

• SubString

Multiple Choice

16. (c) Using a programming language of your choice (VISUAL BASIC!), state the pre-defined function used to convert:

(ii) ASCII to Character

• CHR

• MOD

• ASC

• SubString

Open Ended

16. (d) An execution error occurs for some values of "message" or "shiftLettersBy".

Explain why this happens.

Open Ended

16. (e) The function could be re-written to reverse the characters in the message string.

For example, inputting ‘jfx’ would produce the output ‘xfj’.

Using a recognised design technique, design an algorithm to reverse and store the new message.

Open Ended

17. In Formula One motor racing, teams can enter two drivers for each race. Every driver has a unique number on their car, which is allocated annually at the start of each new racing season.

A database is required to store data on the teams, drivers and race results since the sport started in 1950. Users would be able to collate information on team or driver wins to find the most successful racers or find how the success of teams has changed over the years.

(a) State two functional requirements of the above database.

Open Ended

17. (b) The entity-relationship diagram below shows how information on the teams, drivers and the races since 1950 could be stored. There are errors in the design. Describe three errors in the design.

Draw

17. (i) Complete the table below to show the output from the following

SQL statement.

SELECT country, SUM(championshipWins)

FROM Team

GROUP BY country

ORDER BY country ASC;

Draw

17. (ii) Design a query using wildcards, to find and display all the teams formed in the 1950s.

Open Ended

18. (a) The data from the file is imported into an array of records.

(i) Using a programming language of your choice, define a suitable record structure.

Open Ended

18. (a) The data from the file is imported into an array of records.

(ii) Using a programming language of your choice, declare a variable

that can store the data for 5000 participants.

Open Ended

18. (c) A participant manages to access the file and change their own score.

State two different offences the participant has committed under the Computer Misuse Act 1990.

Draw

20. (a) Complete the table below to show the data flow in and out of steps 2

and 3.

Open Ended

20. (b) Using a recognised design technique, refine step 2.

Open Ended

20. (c) Using a recognised design technique, refine step 4.

Multiple Select

(d) The program is modular and uses procedures.

Which are benefits of designing a modular solution to this program.

• Different programmers can implement different parts of the design

• Easier to implement as there is no need for parameter passing

• Each part of the design can be tested separately when implemented

• Design shows main processes

Poll

Do you enjoy this as a task / find this a good way to revise?

• Yes

• No

• Maybe

• Depends on the final scores!