Electricity Flashcards
How do we use electricity?
-Lights
-Communication
-Heat
-Medical Devices
-Appliances
What is the transfer of electrons called?
Static electricity
What are the three laws of charges?
-Unlike charges attract
-Like charges repel
-Charged objects attract uncharged (neutral) objects
What are conductors? What are three examples?
Conductors are materials that allow charges to move freely. Examples of these are copper wiring, tap water, and metals.
What are insulators? What are three examples?
Insulators are materials that do not allow charges to pass easily through them. Examples of these are rubber, plastic, and wooden materials.
What are semiconductors?
Semiconductors are materials that have:
-Higher conductivity than insulators
-Lower conductivity than metals
What are superconductors?
Materials that offer little, if any, resistance to the flow of charge.
What is electric discharge?
Rapid redistribution of charge between two objects.
What is grounding?
Means to connect to the earth so charge build ups are prevented.
What are ways you can prevent static buildup?
-Humidifiers
-Dryer sheets
-Anti static sprays
-Grounding wires
What is a circuit?
A circuit provides a continuous for electrical charges.
What are the four main parts in a circuit and what are examples of each?
-Source (battery)
-Conductor (wires)
-Load (light bulb)
-Control (switch)
What is current?
Current is the amount of charge that passes a point in a conducting wire every second.
What is voltage? What is it also called?
The change in energy between two points in a circuit (energy is lost going through a device). Voltage is also called potential difference.
What is resistance?
The property of a substance to hinder the motion of charge.
What factors affect resistance?
-Length of wire
-Cross-section area
-Temperature of wire
-Material
What are resistors?
Materials used to control current or voltage.
What are the two types of circuits and what is the difference?
-Series circuit - have only one current path
-Parallel circuit - have several paths
What are the two laws of thermodynamics?
- Energy cannot be created or destroyed, only converted from one form to another
- In any energy transfer, some energy is lost to the surroundings as waste energy.
What is a thermocouple?
a loop of two wires made of different types of metals.
What is a thermo-electric generator?
A device that uses thermocouples to create usable electricity.
What is the Piezoelectric effect?
Sound produced when an electric current passes through a quartz crystal.
How can light be used to create electricity?
Using a photovoltaic cell (solar cell).
What is a Electrochemical Cell?
A device that converts energy stored in chemicals (metals) into electrical energy.