Electronics Quiz – Printable Version
20 multiple-choice questions with an explained answer key, ready to print.
Print the sheet (or save it as a PDF from the print window), hand it out, then mark it together using the answer page: every answer is explained. Perfect for a party, a birthday, a classroom, a care home or a team activity.
Name: ………………………………Score: ……… / 20
- What is the main function of a capacitor in electronics?
- A. Amplify the current
- B. Measure the voltage of a circuit
- C. Temporarily store an electric charge
- D. Convert light into electricity
- What does the acronym LED, widely used in electronics, stand for?
- A. Light Emitting Diode
- B. Low Energy Device
- C. Light Electric Display
- D. Linear Electric Driver
- What are the two most commonly used semiconductor materials in electronics?
- A. Silicon and germanium
- B. Gold and silver
- C. Iron and nickel
- D. Copper and aluminum
- Which rechargeable battery technology powers most smartphones and laptops today?
- A. Alkaline battery
- B. Mercury battery
- C. Lithium-ion battery
- D. Lead-acid battery
- What is the role of soldering in electronics?
- A. Measure the resistance of a wire
- B. Cool down a printed circuit board
- C. Create a permanent electrical connection between components
- D. Electrically insulate two components
- What is a reflow oven used for in the manufacturing of electronic boards?
- A. To chemically clean printed circuit boards
- B. To melt the solder paste and solder all SMD components at once
- C. To test the heat resistance of components
- D. To quickly cool components after testing
- What is the role of a cleanroom in semiconductor manufacturing?
- A. Store finished components away from light
- B. Cool down the production machines
- C. Test the mechanical strength of chips
- D. Maintain very pure air to limit particles that could damage circuits
- What does automated optical inspection (AOI) check in electronics production?
- A. The final weight of the finished product
- B. The quality of component placement and soldering on the board
- C. The ambient temperature of the workshop
- D. The voltage of the workshop's electrical grid
- Where do radio waves sit in the electromagnetic spectrum relative to visible light?
- A. They have exactly the same frequency
- B. They are not part of the electromagnetic spectrum
- C. They have a much lower frequency and a much longer wavelength
- D. They have a much higher frequency
- How is the binary system (0 and 1) physically represented in an electronic circuit?
- A. By the weight of the component
- B. By the temperature of the circuit
- C. By two distinct voltage levels (high and low)
- D. By the color of the components
- What is a Faraday cage used for?
- A. To cool down electronic components
- B. To store solar energy
- C. To block external electromagnetic fields
- D. To amplify radio waves
- Which technology lets an access badge or anti-theft tag be read at a distance, without contact or a battery?
- A. Wi-Fi
- B. RFID (radio-frequency identification)
- C. Laser
- D. Barcode
- What is the shrill whistle produced when a microphone picks up the sound of its own loudspeaker called?
- A. Audio feedback (the Larsen effect)
- B. The Doppler effect
- C. The Joule effect
- D. The greenhouse effect
- Why do most smartphone touchscreens not respond when you wear ordinary gloves?
- A. Because they measure the finger's heat
- B. Because they need the pressure of a nail
- C. Because they detect the slight electrical charge conducted by the skin
- D. Because gloves block the light
- What is the big practical advantage of the USB-C plug?
- A. It is reversible and plugs in either way
- B. It is square
- C. It is only for headphones
- D. It only exists on Apple computers
- What does the abbreviation 'IoT' stand for?
- A. Integrated Output Technology
- B. A security protocol
- C. A video format
- D. The Internet of Things
- Where does the green colour of most printed circuit boards come from?
- A. Silicon
- B. Copper oxidation
- C. The protective solder mask covering the copper tracks
- D. A mandatory military standard
- Which metal is the best conductor of electricity?
- A. Copper
- B. Gold
- C. Aluminium
- D. Silver
- Which Danish physicist discovered in 1820, by watching a compass needle move, that an electric current creates a magnetic field?
- A. Niels Bohr
- B. Hans Christian Ørsted
- C. André-Marie Ampère
- D. Georg Ohm
- What does "CPU" stand for in a computer?
- A. Working memory
- B. The graphics card
- C. The power supply
- D. The Central Processing Unit
Answer key — Electronics Quiz
- C. Temporarily store an electric chargeA capacitor stores electrical energy as charge between two conductive plates separated by an insulator, and can release it quickly.
- A. Light Emitting DiodeAn LED is a diode that emits light when current flows through it, through a phenomenon called electroluminescence.
- A. Silicon and germaniumSilicon, abundant and stable, is the most widely used semiconductor today, while germanium was used in early transistors before being largely replaced.
- C. Lithium-ion batteryThanks to its high energy density and light weight, the lithium-ion battery, commercialized at scale since the 1990s, now powers most portable electronic devices.
- C. Create a permanent electrical connection between componentsSolder melts a metal alloy to create a durable electrical and mechanical junction between a component and a printed circuit board.
- B. To melt the solder paste and solder all SMD components at onceA reflow oven gradually heats the board according to a precise thermal profile to melt the previously applied solder paste, soldering all SMD components on the board in a single operation.
- D. Maintain very pure air to limit particles that could damage circuitsA cleanroom is classified according to the number of particles allowed per volume of air; this control is essential since the smallest dust particle can destroy the microscopic structures etched onto a silicon chip.
- B. The quality of component placement and soldering on the boardAn automated optical inspection system uses cameras and image processing to detect, right after placement or soldering, components that are misplaced, missing, or poorly soldered on an electronic board.
- C. They have a much lower frequency and a much longer wavelengthRadio waves occupy the part of the electromagnetic spectrum with the lowest frequencies and longest wavelengths, well below visible light.
- C. By two distinct voltage levels (high and low)In a digital circuit, 0 and 1 usually correspond to two different voltage levels (for example, about 0V for 0 and 3.3V or 5V for 1).
- C. To block external electromagnetic fieldsA Faraday cage, made of a conductive material, redistributes external electric charges across its surface, thereby shielding its interior from electromagnetic fields, as used in certain electronic shielding applications.
- B. RFID (radio-frequency identification)The tag is powered by the reader's own radio wave. It is found in passports, ski passes and even under pets' skin.
- A. Audio feedback (the Larsen effect)The sound loops round, getting louder each time. The French name comes from Danish physicist Søren Absalon Larsen.
- C. Because they detect the slight electrical charge conducted by the skinThese 'capacitive' screens respond to the finger's conductivity.
- A. It is reversible and plugs in either wayNo more flipping the plug three times! Since 2024, the European Union has required it as the universal charger for phones and many devices.
- D. The Internet of ThingsConnected thermostats, watches, light bulbs and fridges. There are now billions of internet-connected objects, more than people on Earth.
- C. The protective solder mask covering the copper tracksThis 'solder mask' insulates the tracks and stops solder flowing where it should not.
- D. SilverSilver narrowly beats copper but is far more expensive. That is why cables are copper, and gold is mainly used for non-corroding contacts.
- B. Hans Christian ØrstedMade during a lecture, this discovery linked electricity and magnetism for the first time.
- D. The Central Processing UnitIt is the computer's "brain": it executes programs' instructions billions of times per second.