What is an insulator?
A material that blocks or resists the flow of a current.
What is a conductor?
A material that allows a current to flow through it easily
What is a resistor?
An electrical component that limits or regulates the flow of electrical current in an electronic circuit. They can also be used to provide a specific voltage
Voltage
The amount of energy applied per unit of charge to make electrons move through a circuit.
Where do electrons get the energy they carry around the circuit?
Energy sources
When do electrons lose energy?
When they pass through components such as light globes and motors
What are volts measured with and what unit is used?
Using a voltmeter, and V is used
The voltage is high if…
The electrons are supplied with a lot of energy or lose a lot of energy
The voltage is low if…
The electrons are not supplied with lots of energy or do not lose a lot of energy
The voltage is zero if…
The battery is dead, the power point is turned off, or the electrons are losing no energy at that point in the circuit
What is a current?
An electric current is formed whenever charges flow from one spot to another
What is current measured by, and what unit?
An ammeter measures the amount of charge that flows through it every second, and is measured in A
If the current is low…
not much energy flows through it per second
If the current is high…
a lot of energy flows through it per second
Resistance
As electrons pass through a wire, the amount their path is restricted is resistance
What does resistance measure?
How difficult it is for an electric current to pass through a material or component
When electrons bump into more materials and obstacles as they pass through a circuit…
The resistance is higher, and they lose more energy and voltage
How is energy lost in an electric circuit?
Every time electrons bump off course of into an obstacle
How does resistance affect current?
The more resistance, the harder it is to get through, reducing the current getting through it
Factors that affect resistance
Thickness of a wire
Length of a wire
Type of material the wire is
How does the type of material a wire is affect its resistance?
If a material is more insulating, it is more resistance. For example, metal is a better conductor than rubber because it has less resistance.
How does the length of a wire affect resistance?
The longer a wire is, the more obstacles it has to pass through
How does the thcikness of a wire affect its resistance?
Electrons find it harder to pass through thinner wires than thicker wires, as there is less space
What can resistance be measured in and with?
Ohms Ω, using a multimeter
