Green Power & the Planet
Circuits & Safety
Seeing the Invisible
Smart Security System
Magnetic Mysteries
Blast to the Past
100
Why are greenhouse gases harmful?
Gases like CO₂ trap heat in Earth’s atmosphere, causing global warming.
100
What is a circuit?
A loop that lets electricity flow through to power devices.
100
What does “IR” stand for?
Infrared
100
What is the main purpose of a security system?
To protect people and property by detecting and alerting danger.
100
What is created around a wire when electricity flows through it?
A magnetic field.
100
What are the three essential parts of any simple circuit?
Source, Path, Load.
200
Name two renewable energy sources.
Solar, wind, hydropower, bio, and geothermal energy.
200
What’s the difference between open and closed circuits?
Closed = electricity flows (like a light on)
Open = electricity stops (like a light off).
200
What is the main difference between active and passive IR sensors?
Active IR sends out a beam and detects reflection; Passive IR senses heat radiation.
200
What does a tilt switch do?
It detects if something is tipped or moved from level position.
200
What is an electromagnet?
A magnet powered by electric current that can be turned on and off.
200
AC vs. DC: Which one comes from wall outlets, and which one comes from batteries?
AC = wall outlets; DC = batteries.
300
How do solar panels create electricity?
They collect sunlight in solar cells that convert light into direct current (DC).
300
What is a parallel circuit
A parallel circuit is an electrical circuit where multiple components are connected across separate branches, allowing current to split and flow through each path simultaneously
300
Name a device that uses an IR sensor.
TV remote, automatic door, or security light.
300
How does a magnetic reed sensor work?
It uses a magnet to close a circuit when doors or boxes are shut.
300
How can you make an electromagnet stronger?
Add more wire coils or increase the current.
300
What’s the difference between static electricity and current electricity?
Static stays in one place; current flows through a path/loop.
400
What machine does wind power use to generate electricity?
A wind turbine spins a generator to produce electricity.
400
Name one reason why we hide circuits inside devices.
For safety, protection, and design —to keep them clean and safe to touch.
400
Why might IR sensors not work well in sunlight?
Bright light interferes with infrared signals and confuses the sensor.
400
Name one real-world object that uses a tilt switch.
Pinball machine, car alarm, or treasure box alarm.
400
How do motors use magnetism to move?
They turn electric energy into motion by spinning a magnetic coil.
400
On a breadboard, what are the long edge strips called, and what do we usually connect to them?
They are power rails
connect + (red) – (blue/black) from the battery.
500
Why are renewable energies important for AI data centers?
They reduce pollution while meeting the growing electric demand from AI servers.
500
Why is polarity important when building a circuit?
Electricity must flow in the right direction (+ to –) or parts won’t work.
500
What is a JK Flip Flop used for in an IR circuit?
It stores on/off memory so a signal can toggle a light or motor.
500
How are VEX IQ and Scratch similar in coding?
Both use block-based logic with loops, events, and if/then blocks to control outputs.
500
What’s the difference between a permanent magnet and an electromagnet?
Permanent magnets always stick; electromagnets only work with electricity flowing.
500
In a series circuit with two LEDs, why do they get dimmer than in parallel?
In series they share the same current/voltage drop across more parts; in parallel each branch gets full supply voltage.