CAIE AS Level Computer Science

Elsa is learning about binary numbers in her computer science class. She wants to know the binary representation of the decimal number 65. Can you help her find the correct binary representation?

• A) 01000001

• B) 1000001

• C) 1100001

• D) 0000001

Answer explanation

The decimal number 65 converts to binary as 01000001. This is the correct representation, matching choice A. Choices B, C, and D represent different decimal values.

During a computer science class, Elsa asked how many bits per character the ASCII character encoding standard uses. Fill in the blank: The ASCII character encoding standard uses ___ bits per character.

• 7

• 8

• 16

• 32

Answer explanation

The ASCII character encoding standard uses 7 bits per character, allowing for 128 unique symbols. This is why the correct answer is 7, as it defines the basic set of characters used in text representation.

Elsa is editing a photo for her school project and decides to increase the color depth of the image. What effect will this have?

• Decreases file size

• Improves color quality but increases file size

• Reduces color quality

• Has no effect on file size

Answer explanation

Increasing color depth enhances the range of colors an image can display, resulting in improved color quality. However, this also leads to larger file sizes due to the increased data required to represent the additional colors.

During a graphic design class, Elsa and William learned that vector graphics are made up of ______.

• Pixels

• Drawing objects

• Sound waves

• Bits

Answer explanation

Vector graphics are composed of drawing objects, such as shapes and lines, which are defined mathematically. Unlike raster graphics made of pixels, vector graphics can be scaled without losing quality.

William and Sue are discussing how to store their digital photos. William suggests using lossless compression, while Sue prefers lossy compression. What is the main difference between these two methods?

• Lossless compression reduces file size without losing any data, while lossy compression reduces file size by eliminating unnecessary data.

• Lossless compression eliminates unnecessary data, while lossy compression retains all data.

• Lossless compression is used for sound files, while lossy compression is used for text files.

• Lossless compression is irreversible, while lossy compression is reversible.

Answer explanation

The correct choice highlights that lossless compression retains all data while reducing file size, whereas lossy compression achieves smaller sizes by discarding some data deemed unnecessary.

Fill in the blank: Sue set up a LAN to connect devices within a ______ geographical area in her office.

• large

• small

• global

• virtual

Answer explanation

A LAN (Local Area Network) is designed to connect devices within a small geographical area, such as a home, office, or building. This distinguishes it from larger networks like WANs, which cover broader areas.

William and Elsa are setting up a new internet connection for their office. They are considering using fiber-optic cables. What is one of the benefits they can expect from using fiber-optic cables?

• Less expensive and easier to install

• Greater bandwidth and improved security

• Affected by electromagnetism

• Needs expensive optical transmitters

Answer explanation

Fiber-optic cables offer greater bandwidth, allowing for faster data transmission, and improved security due to their resistance to electromagnetic interference, making them a superior choice over traditional cables.

In a bus topology, if Elsa and William are communicating, other computers can read the data being sent between them. This topology is unsuitable for heavy traffic due to frequent ______.

• Collisions

• Interference

• Delays

• Errors

Answer explanation

In a bus topology, multiple computers share the same communication line. When two devices transmit simultaneously, it leads to collisions, causing data loss and requiring retransmission, making it unsuitable for heavy traffic.

William and Rianne are setting up a new office network. What is the most common wired medium for data transmission in LANs or WANs?

• Wi-Fi

• Bluetooth

• Ethernet

• Fiber Optic

Answer explanation

Ethernet is the most common wired medium for data transmission in LANs and WANs due to its reliability, speed, and cost-effectiveness, making it the standard choice for networking.

During a group project, Elsa and William are using a shared online document. If both try to edit the same section at the same time, what should happen next?

• They stop editing permanently.

• They wait a random time before retrying.

• They switch to a different document.

• They increase their internet speed.

Answer explanation

In CSMA/CD, when a collision occurs, the device does not stop transmitting permanently. Instead, it waits a random time before retrying to avoid repeated collisions, making 'waiting a random time' the correct response.