Level:
Correct: 0
Incorrect: 0
Marks: 0/0
Exam Practice
Subject:
Topics:
Cambridge IGCSE Computer Science (Paper 1) Smart practice A mixed round aimed at your weak spots
Unit 1
Data representation
Number systems
Binary, denary and hexadecimal conversions
0%
Uses of hexadecimal
0%
Binary addition and overflow
0%
Logical binary shifts
0%
Two's complement
0%
Text, sound and images
Character sets: ASCII and Unicode
0%
Representing sound
0%
Representing images
0%
Data storage and compression
Data storage units and file size calculations
0%
Data compression
0%
Unit 2
Data transmission
Types and methods of data transmission
Packets and packet switching
0%
Methods of data transmission
0%
The USB interface
0%
Methods of error detection
Parity, checksum and echo check
0%
Check digits and ARQ
0%
Encryption
Encryption
0%
Unit 3
Hardware
Computer architecture
The CPU, Von Neumann architecture and the FDE cycle
0%
Cores, cache and clock speed
0%
Instruction sets and embedded systems
0%
Input and output devices
Input devices
0%
Output devices
0%
Sensors
0%
Data storage
Primary storage: RAM and ROM
0%
Secondary storage: magnetic, optical and solid-state
0%
Virtual memory and cloud storage
0%
Network hardware
Network hardware: NIC, MAC and IP addresses, routers
0%
Unit 4
Software
Types of software and interrupts
System software, application software and operating systems
0%
Firmware and interrupts
0%
Programming languages, translators and IDEs
High-level languages, low-level languages and assembly language
0%
Compilers and interpreters
0%
Integrated development environments (IDEs)
0%
Unit 5
The internet and its uses
The internet and the world wide web
The internet, the world wide web, URLs and HTTP(S)
0%
Web browsers, locating web pages and cookies
0%
Digital currency
Digital currency and blockchain
0%
Cyber security
Cyber security threats
0%
Keeping data safe: security solutions
0%
Unit 6
Automated and emerging technologies
Automated systems
Automated systems
0%
Robotics
Robotics
0%
Artificial intelligence
Artificial intelligence
0%
Avg
score:
–
Topics
done:
0/39

The USB interface

Practise 16 exam-style questions on The USB interface for Cambridge IGCSE Computer Science (Paper 1). Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.

  • 16 questions
  • 1–6 marks each
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16 questions, marked as you go

Sample questions with model answers

Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.

Question 1

1 mark

When a USB device is plugged into a computer, the computer loads a piece of software so that it can communicate with the device.

Name this type of software.

Model answer

A device driver.

Explanation

A device driver tells the operating system how to communicate with a particular device. When a USB device is plugged in, the computer recognises it and loads the matching driver automatically, or asks the user to download it if it is not available.

Mark scheme
  1. 1 mark

    Device driver

    accept 'driver'; do not accept 'operating system' or 'firmware'

Question 2

2 marks

A standard USB 2.0 cable contains four wires.

State the purpose of these wires.

Model answer

Two of the wires supply power to the device (a +5 V wire and an earth wire), and the other two wires carry the data.

Explanation

A USB 2.0 cable has two wires for power and two for data. This is why a USB port can power or charge a device as well as transmitting data, and because the data is serial it needs only a few wires.

Mark scheme
  1. 1 mark

    Two wires supply power to the device (+5 V and earth/ground)

    accept 'two wires are for power'

  2. 1 mark

    Two wires are used for data transmission

    accept 'two wires carry the data'

Question 3

3 marks

A photographer wants to connect an external hard disk drive to a laptop to copy large photo files.

Explain why the USB interface is suitable for this.

Model answer

When the photographer plugs the drive in, the laptop detects it and loads the driver automatically, so no technical knowledge is needed. Modern USB versions transfer data quickly, so large photo files can be copied in a short time. The USB cable can also power the drive, so the photographer does not need a separate power supply when working away from a mains socket.

Explanation

For 'explain why it is suitable', link each benefit of USB to the scenario: large files need a fast transfer rate, a laptop user benefits from the drive being powered by the cable, and automatic detection makes it easy to use.

Mark scheme
  1. 1 mark

    The drive is detected automatically and its driver is loaded, so the photographer does not need technical knowledge

    max 3

  2. 1 mark

    Modern USB versions have fast data transfer rates, so large photo files are copied quickly

  3. 1 mark

    The USB cable can power the drive, so no separate power supply is needed (useful away from a mains socket)

  4. 1 mark

    USB is an industry standard, so the drive will work with the laptop (and with other computers)

  5. 1 mark

    USB is backward compatible, so the drive works even if the laptop has an older USB port

Question 4

4 marks

The table shows the average data transfer rates of two USB connections. A user copies a 4 GiB video file to an external drive.

Calculate how many seconds faster the file is copied using the USB 3.0 connection than using the USB 2.0 connection. Show your working.

Average data transfer rates. Table with columns "Connection", "Average transfer rate". Connection: USB 2.0; Average transfer rate: 32 MiB per second | Connection: USB 3.0; Average transfer rate: 256 MiB per second.

Model answer

4 GiB = 4 × 1024 = 4096 MiB
USB 2.0: 4096 ÷ 32 = 128 seconds
USB 3.0: 4096 ÷ 256 = 16 seconds
Difference = 128 − 16 = 112 seconds faster

Explanation

Convert the file size into the same unit as the transfer rates first (GiB to MiB by multiplying by 1024), then divide by each rate to find the time taken. The question asks how much faster, so subtract the two times; giving just one time is a common way to lose marks.

Mark scheme
  1. 1 mark

    4 GiB = 4 × 1024 = 4096 MiB

  2. 1 mark

    USB 2.0: 4096 ÷ 32 = 128 seconds

    follow through from an incorrect conversion

  3. 1 mark

    USB 3.0: 4096 ÷ 256 = 16 seconds

    follow through from an incorrect conversion

  4. 1 mark

    112 (seconds faster)

    128 − 16; follow through; do not accept an answer using 1000

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