Electricity Flashcards
Come from protons which are positive and electrons which are negative
Electric charges
the accumulation of excess electric charges on an object
Static electricity
electric charges can be transferred from object to object, but it cannot be created or destroyed
Law of Conservation of Charge
+ -
Opposite charges attract
+ +
- -
Like charges repel
materials in which electrons move easily. Ex: metals
Conductors
material in which electrons are not able to move easily. Ex: wood, plastic, rubber
Insulators
process of transferring charge by touching or rubbing
Charging by contact
rearrangement of electrons on a neutral object caused by nearby charged objects.
Charging by induction
the net movement of electric charges in a single direction through a wire or conductor.
Electric current
force that causes electric charges to flow; charges flow from the high voltage to the low voltage.
Voltage
A closed path that electric current follows
Circuit
Current always flows from negative to positive in a DC current
Direction of current flow in circuit powered by battery
chemical reactions occur in a moist paste causing transfer of electrons.
Ex: the battery in the above diagram.
Dry cell
contains two connected plates made of different metals in conducting solution.
Ex: car battery
Wet-cell
tendency for a material to oppose the flow of electrons, changing electrical energy into thermal and light energy
- ex: Making wires thinner, longer or hotter increases resistance
All materials have some electrical resistance, which is measure in ohms ()
Resistance
current in a circuit equals voltage difference divided by resistance
Ohm’s Law
Small piece of metal that bends when it gets hot, opening the circuit and stopping the current flow
Circuit breaker
a temporary magnet made by wrapping a wire coil carrying a current around an iron core. You can increase the strength of the magnetic field by adding more turns to the wire coil (solenoid) or increasing the current passing through the wire.
Electromagnets
a device that changes electrical energy into mechanical energy.
In a simple electric motor, an electromagnet rotates between the poles of a permanent magnet
Electric Motor
current that flows in only one directions through a wire. Ex. A battery
Direct current (DC) current
reverses the direction of the current flow in regular patterns. Ex. Plugging toaster into the wall outlet
Alternating current (AC)
Current has only one loop to flow through. Examples include:
Flashlight, holiday lights
Series Circuit
Contains two or more branches for current to flow through. Examples include:
Homes, automobiles
Parallel circuit
