Electrical Circuits Flashcards
What are particles that carry an electric charge called
Electrons
What is an electric current
A flow of charge
What two things are needed for an electric current to flow
- Something to transfer the energy to the electrons such as a battery
- A complete path for the electrons to flow through (a circuit)
What does a switch do in an electric circuit
It breaks the circuit and let’s it be turned on and off
What should you do when drawing a circuit diagram
Draw circuit symbols first then draw the wires. Do not let the wires cross each other
What is current a measure of
How much electric charge flows through a circuit
What is current measured in
Amperes (A) It is often shortened to Amp
What device is used to measure current
Ammeter
How do you get a reading on an ammeter
By connecting it with the circuit
What is potential difference the measure of
The difference in energy between two parts of a circuit. The bigger the difference in energy the bigger the potential difference
What is potential difference measured in
Volts
What device is used to measure potential difference
Voltmeter
What happens in a series circuit if a lamp breaks or a component is disconnected
Everything stops working
Why would a series circuit be useful
If you want a warning that one component has failed. It also needs less wiring
How does adding more cells to a circuit effect it
It increases the current
Why would a parallel circuit be useful
Because if one component stops working all the others on different branches carry on. Also the lights don’t dim if you add more they will stay the same
What is resistance
How much the wires and other components in a circuit reduce the flow of charge through them
What is resistance measured in
Ohms (symbol is an uppercase Greek letter omega)
When does the resistance increase
When you add more components to a circuit
How do you calculate the resistance
By measuring:
The potential difference
The current
And dividing TPD by TC
Conductors of electricity
Metal elements
Graphite
Mixtures of metals
Salt solution
Insulators of electricity
Most non metals Diamond Plastic Wood Rock
