Event Rules
Each team can bring any notes and resources on paper, in any size, with information from anywhere. What can you put these notes in?
You can use binders, notebooks, folders, plastic sleeves, laminated pages, tabs, and labels.
Electric current
The flow of electrons through a material
What is the rate of flow of charge past a particular point or region called?
Current
In an RC circuit, the switch has been closed for a long time. It is then opened. Explain, without equations, how the direction of current in the capacitor changes at the moment the switch is opened.
Reverses the direction of the current flow.
Teams must keep their notes organized. What can you do during the event to look at your notes?
You can take pages out of your containers and use them at any time during the event.
Conductor
Creates a pathway for electrons
What is the notion of the ability to move a charged particle called?
Voltage
Design a circuit to dim a high-power lamp using a variable resistor. Calculate the power dissipated by the lamp vs. the potentiometer. Explain why this method is inefficient and propose a better approach using the same components
It is highly inefficient because the resistor dissipates wasted energy as heat, rather than reducing power consumption efficiently.
Each team can also bring ___ or ______ and two Class ___ _________ to use at any time.
Pens or pencils, Class III calculators
Insulator
Prevents the flow of electrons
What formula expresses the electrostatic force between two charges?
Coulomb's Law
You need a 5V output from a 12V source, but your load changes resistance frequently. Design a voltage divider that maintains a relatively stable 5V, explaining how to choose the resistor values relative to the load.
Use a voltage divider where the current through the resistors (\(I_{div}\)) is at least 10–20 times higher than the maximum current drawn by the load (\(I_{load}\)). Use a 1.4:1 ratio for \(R_{1}:R_{2}\) (e.g., \(R_{1}=700\Omega ,R_{2}=1k\Omega \)) to maintain stability.
Event Supervisors will give you all the supplies and tools you need for _____-__ _____.
Hands-on tasks
Transistor
A type of switch that contains no moving parts and uses electricity to turn itself on and off
Networks of ________ between two points can be simplified into an equivalent single _________, for which the resistance can be calculated according to the configuration and values of the ___________ within the network.
Resitor
Design a circuit using a Light Dependent Resistor (LDR) to turn on an LED when it gets dark. Explain the reasoning behind where you place the LDR in a voltage divider to ensure the output voltage goes up when light goes down.
Place the LDR between the voltage output (base of a transistor) and Ground, while a fixed resistor is placed between the positive supply and the output.
You can bring your own ____ ___________ to use instead of the ones provided, if the event supervisor allows it.
Basic Multimeters
Resitor
A device used to control current in an electric circuit by providing resistance
What is a device that stores a charge called?
Capacitor
You are using a Wheatstone bridge to measure an unknown resistor. If the galvanometer shows current, explain how you would adjust the known resistors to determine the direction of the error in your measurement.
Adjust the variable resistor (or slide wire) and observe the galvanometer deflection direction. If increasing moves the deflection closer to zero, was too low. If deflection moves further from zero, was too high. The goal is to reach a "null" point (zero current).