Electrical Circuits Flashcards
Ammeter
A device used to measure the current at a single point in a circuit
An ammeter gives a reading in amperes (A) that can be positive or negative, depending on which direction electrons flow.
Ampere
The standard unit of electrical current
Amperes or amps have the symbol A. A hair dryer requires about 14 A of 12 volt power to run.
Battery
A component that stores chemical energy to be used as a power source
When battery terminals are connected by a wire, chemical energy is transferred to electrons and causes them to flow.
Curcuit
A pathway for electricity to flow around
A circuit must include a source of electricity, like a battery, and something to conduct electricity, like a wire.
Circuit Diagram
A model of the components of a circuit and how they are connected
Circuit diagrams use special symbols for the components and ruled lines to show their connections.
Closed Circuit
A complete pathway that allows electrical current to flow
A closed circuit has no gaps or open switches. Electricity can flow.
Component
Part of an electrical circuit
Components of electrical circuits include batteries, wires and lamps.
Electrical Current
The flow of** electrons** through a circuit
Electrons flow along a wire from an area of negative charge to an area of positive charge.
Electron
A very small subatomic particle with negative charge
Electrons furthest from the nucleus of an atom can be forced to move from one atom to another.
Lamp
A component that produces light
A light-emitting diode (LED) is a type of lamp that can operate with a very small amount of power.
Multimeter
A device that can measure both resistance and voltage
A multimeter can be set to measure resistance, voltage or electrical current using a control dial.
Negitive terminal
The part of a battery that electrons flow out from
The negative terminal is a source of electrons that flow out of the battery and around the circuit.
Ohm
The standard unit of electrical resistance
Ohms are symbolized by the Greek letter omega (Ω). The wires in a circuit usually have a resistance close to 0 Ω.
Ohms Law
The relationship between **current, voltage and resistance
**
Electrical current is directly proportional to voltage and inversely proportional to resistance.
Open Cicuit
A broken pathway that does not allow electrical current to flow
An open circuit can be caused by an open switch, a frayed wire or a loose connection. Electricity cannot flow.
Positive Terminal
The part of a battery that electrons flow towards
The positive terminal contains positively charged ions that accept electrons flowing through a wire.
Resistance
A material’s opposition to the flow of electrical current
The higher the resistance of a component, the harder it is for electrons to flow and the more energy they lose as heat.
Resistor
A component designed to lower the current passing through a circuit
A resistor is made from a material with high resistance to slow down the movement of electrons.
Switch
A component used to open or close a circuit
Switches can make or break the connection in an electrical circuit to turn a device on and off.
Terminal
Part of a component where electrical current can leave or enter
Electrical current can flow from a battery when a closed circuit connects its terminals.
Volt
The standard unit of voltage
Volts have the symbol V. A fully charged AA battery can provide a voltage of 1.5 V.
Voltage
The amount of energy or ‘push’ given to electrons moving in a circuit
The higher the voltage supplied to a circuit, the bigger the ‘push’ the electrons receive.
Voltmeter
A device used to measure the voltage between two points in a circuit
A voltmeter gives a reading in volts (V) that can be positive or negative, depending on which direction electrons flow.
Wire
A component made of a flexible strand of conductive metal
Metals such as copper, aluminium and nickel are commonly used to make electrical wires.
