electricity
Van Graaff generator A machine that produces an electrostatic charge. This is used to accelerate particles in x ray machines, food sterilizers, and process machines.
Electrostatic charge The build up of electric charge on the surface of an object
Electric energy Energy carried by electric currents when going through a circuit
Dry cell An object, such as a torch battery, that uses a chemical reaction to produce electrical energy
Wet cell An object, such as a car battery, that uses a chemical reaction to produce chemical energy.
Electrical conductor A material through which charged particles are able to move. Example, copper.
Electrical insulator A material that prevents the movement of charged particles. Example, plastic.
Insulator a substance that prevents the movement of thermal or electrical energy.
Semi conductor A material that conducts electricity more than an insulator and less than a conductor. It’s conductivity can be charged by adding other substances to it. Example, germanium and silicon in their pure form.
Electric circuit a closed pathway that conducts electrons in the form of electrical energy.
Like charges The charges on an object are the same. They repel.
Unlike charge The charges on an object are different. They attract.
Electric current The flow of electric charge through a circuit. Measured by counting the number of electrons that get past a point every 1 second.
Circuit diagram A diagrammatic way to represent an electric circuit
Positive terminal The point in the circuit where electrons flow into
Negative terminal The point in the circuit where electrons flow out from.
Conventional current Current flows out from the positive terminal, and into the negative terminal of the source.
Alternating current The flow of electrons reverses directions 50 times every second
Direct current The electrons flow in one direction only. Found in battery powered circuits.
Ampere A large unit of current. 1000mA (milliampere) =1A
Switch Controls the flow of current by opening or closing the circuit.
Voltmeter Measures the voltage between two points in the circuit.
Parallel A way of connecting loads so they are all connected to the battery separately, they are in parallel to each other.
Series Describes an electric circuit arranged with the loads connected in a row, so the energy passes through one load at a time.
Short circuit When the current flows through a different path than the one intended.
Fuse A wire of high resistance: melts if too much current flows in a circuit.
Compare parallel and series circuit. In a series circuit, batteries are connected end to end, and the light globe components share the energy sourced from the battery (Voltage is divided). In a parallel circuit, light globes are parallel to eachother, where each electron gains energy from each component it passes through, voltage sourced from the power source is the same across all components.
Voltage Voltage is the measure of the electric potential difference between two points in a circuit.
Resistance The measure of how difficult it is for charged particles in a circuit to move
Resistors Placed in a circuit to control or reduce the size of a circuit.
Rectifier A device that converts AC to DC, commonly composed of diodes.
Light emitting diode A type of diode that emits light of a particular color and restricts current flow to one direction only. Emits red, yellow green, ultraviolet and infared red.
Photo conductivity how certain materials change their ability to conduct electricity when exposed to light,
Light dependent resistor A resistor that changes resistance according to the amount of light it is exposed to
Thermistor Change resistance based on temperature
Diode A semiconductor device that allows current to flow in one direction only