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

Input devices

Practise 30 exam-style questions on Input devices 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.

  • 30 questions
  • 1–6 marks each
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20 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

State the name of the component in a digital camera that converts the light coming through the lens into electrical signals.

Model answer

The image sensor (a CCD or CMOS sensor).

Explanation

The lens focuses light onto the image sensor, which is made up of millions of tiny light-sensitive elements. Each one produces an electrical signal that is converted into a binary value for one pixel.

Mark scheme
  1. 1 mark

    (Image / light) sensor

    accept 'CCD', 'charge-coupled device' or 'CMOS (sensor)'; do not accept 'lens', 'memory card' or 'shutter'

Question 2

2 marks

A capacitive touch screen does not respond when the user is wearing ordinary gloves.

Explain why.

Model answer

A capacitive touch screen detects a touch because a finger, which conducts electricity, changes the electrostatic field on the screen at that point. Ordinary gloves are insulators, so they do not change the field and the touch is not detected.

Explanation

Capacitive screens rely on the electrical properties of the finger, not on pressure. Special gloves with conductive fingertips, or a conductive stylus, will work.

Mark scheme
  1. 1 mark

    A capacitive screen detects a touch by a change in the electrostatic field / capacitance at the point touched

  2. 1 mark

    This needs a conductor such as a bare finger; gloves are insulators / do not conduct electricity, so the field does not change

    accept 'gloves stop the electrical charge from the finger reaching the screen'

Question 3

3 marks

Describe how a capacitive touch screen detects where it has been touched.

Model answer

A capacitive touch screen is coated with a transparent conductive material, which creates an electrostatic field across the screen. A finger conducts electricity, so touching the screen changes the field at that point. Sensors detect the change, and a microprocessor calculates the coordinates of the touch.

Explanation

Capacitive screens detect the electrical effect of a finger, not pressure, so a light touch works but an ordinary glove does not. Describing layers being pressed together is the resistive method and earns no credit here.

Mark scheme
  1. 1 mark

    The screen has (glass) layers coated with a transparent conductive material

    max 3

  2. 1 mark

    An electrostatic field / small current is spread across the screen

  3. 1 mark

    A finger is a conductor, so touching the screen changes the electrostatic field / capacitance at that point

    accept 'some charge is drawn from the screen at that point'

  4. 1 mark

    Sensors (e.g. at the corners / in a grid) detect the change

  5. 1 mark

    A microprocessor calculates the coordinates of the touch

    do not accept a description of two layers being pressed together

Question 4

4 marks

Compare resistive touch screens and capacitive touch screens.

Model answer

Both types detect the position of a touch so that a microprocessor can calculate its coordinates. A resistive screen detects pressure, so it works with a stylus or a gloved finger, whereas a capacitive screen detects the change in electrostatic field caused by a bare finger. Resistive screens are cheaper, but capacitive screens are clearer in sunlight, more durable and support multi-touch gestures such as pinch to zoom.

Explanation

The underlying difference (pressure compared with electrical detection) explains most of the others, such as the glove issue. Write each point as a comparison so that both screen types are covered.

Mark scheme
  1. 1 mark

    Resistive screens detect pressure (two layers pressed together), whereas capacitive screens detect a change in the electrostatic field caused by a finger

    max 4; each difference must make both sides clear (or use a clear comparative); max 1 for similarities

  2. 1 mark

    Resistive screens work with any object (stylus, gloved finger), whereas capacitive screens need a bare finger / special stylus

  3. 1 mark

    Resistive screens are cheaper than capacitive screens

  4. 1 mark

    Capacitive screens support multi-touch (e.g. pinch to zoom), whereas resistive screens usually do not

  5. 1 mark

    Capacitive screens are clearer / easier to see in sunlight than resistive screens

  6. 1 mark

    Capacitive screens are more durable (glass surface), whereas the flexible top layer of a resistive screen can be scratched / damaged

  7. 1 mark

    Capacitive screens respond to a light touch / are more responsive than resistive screens

  8. 1 mark

    Similarity: both detect the position of a touch and a microprocessor calculates its coordinates

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