N5 Computing Science: SDD + CS Exam Questions

Convert the following 8-bit binary number into denary.

1011 0111

Answer explanation

Remember that each bit represents a different power of 2, so 1, 2, 4, 8, 16, etc.

Why may it be necessary to return to the implementation stage of an

iterative development process after the testing stage?

• To correct errors

• To add new features

• To change the programming language

• To charge the client more money

Answer explanation

Iterative means repetitive so after each stage of the SDP it may be necessary to return to an earlier stage to make change.

The code shown monitors the speed of a vehicle. Choose the actions that correspond with what happens in lines 6 to 9 above if the sensor detects a value of 83 at line 5.

• compares 83 to 70

• condition is false so doesn’t enter loop

• sends signal to alarm

• condition is true so enters loop

• new speed is detected from sensor

Answer explanation

In this case the Boolean condition is False so the program does not enter the loop and skips to the first line after the loop.

The Bank of Aberdeen uses a firewall and encryption to ensure data is kept

secure.

Which description best explains the purpose of a firewall.

• Restricts access to a network for unauthorised users

• Scrambles data to make ir unreadable

• Allows customers to acces their banking online

• Prevents viruses and malware from entering the network

Answer explanation

The correct option is 1. A firewall is a security system that is designed to restrict access to a network for unauthorized users. It acts as a barrier between a private internal network and the public internet, controlling the flow of traffic and preventing unauthorized access to the network. It can also be configured to block certain types of traffic, such as viruses and malware, from entering the network. Encryption, on the other hand, is a process of converting data into a code to make it unreadable to unauthorized users.

The Bank of Aberdeen uses a firewall and encryption to ensure data is kept

secure.

How can encryption help keep data secure?

• Data is encoded and therefore unreadable

• Prevents unauthorised users from accessing data

• Prevents malware from entering the network

• Data is stored in a database using a special key

Answer explanation

The correct option is 1. Encryption helps keep data secure by encoding it in a way that makes it unreadable to anyone who does not have the key to decrypt it. This means that even if someone gains access to the encrypted data, they will not be able to read or use it without the key. This helps to protect sensitive information from being accessed or stolen by unauthorized users.

An ASCII character set contains control characters.

Choose one example of a control character.

• Cancel

• Space

• Delete

• #

Answer explanation

The solution to the given question is option number 1, Cancel. The first 32 ASCII characters are the so-called non-printable characters, also known as control characters. They include keys like Esc, Tab, Shift, etc.

An ASCII character set contains printable characters.

Choose one example of a printable character.

• Space

• Null

• Escape

• Backspace

Answer explanation

The solution to the given question is option number 1, which is Space. ASCII character set is a standard set of characters that are used to represent text in computers and other devices. Printable characters are those characters that can be displayed on the screen or printed on paper. Space is a printable character that is used to create a blank space between words or sentences. Null, Escape, and Backspace are also ASCII characters, but they are not printable characters. Null is a control character that represents the end of a string, Escape is a control character that is used to initiate a special command sequence, and Backspace is a control character that moves the cursor back one position.

A vector graphic file stores objects and their attributes.

State the type of vector object shown.

Answer explanation

For N5 Computing Science you should be familiar wiht rectangles, ellipses, lines and polygon vector objects.

A vector graphic file stores objects and their attributes.

Choose two attributes of this object.

• Co-ordinates of centre

• Fill colour

• Number of sides

• Angle of corner

Answer explanation

The solution to the given question is that the two attributes of an object that can be stored in a vector graphic file are the co-ordinates of the centre and the fill colour. Vector graphics are created using mathematical equations to define the shapes and lines, and these attributes are used to define the appearance of the object. The co-ordinates of the centre are used to position the object on the canvas, while the fill colour is used to define the colour or pattern that fills the object. The other options, such as the number of sides and angle of corner, are specific attributes of certain shapes and may not be applicable to all objects in a vector graphic file.

Jane is entering an online competition. She edits a recording of herself singing

to save and upload to the competition’s website.

Describe one advantage and one disadvantage of saving and uploading an

MP3 file format rather than a WAV file format to the website.

• Can be uploaded quickly

• Disadvantage

• Sound quality is poorer than original

• Advantage

• Uses psychoacoustic

  modelling techniques

• Neither

Answer explanation

MP3 files are compressed so are smaller than the (uncompressed) .wav file. They use psychoacoustic modelling techniques to eliminate unecessary frequencies from the audio.