Electricity Unit Notes
Atoms…
- Have neutrons, protons, and electrons.
- Protons are positively charged.
- Electrons are negatively charged.
Electrons…
- Are located on the outer edges of atoms…they can be moved.
- A Concentration of electrons in an atom creates a net negative charge.
- If electrons are stripped away, the atom becomes positively charged .
Law of Charges
a. Opposite charges attract.
b. Like charges repel.
Static Electricity
- The build up of an electric charge on the surface of an object.
- The charge builds up but does not flow.
- Static electricity is potential energy. It does not move. It is stored.
Static Discharge from Static Electricity
Occurs when there is a loss of static electricity due to three possible things:
- Friction - rubbing
- Conduction – direct contact
- Induction – through an electrical field (not direct contact)
Current Electricity
Current: The flow of electrons from one place to another.
- Measured in amperes (amps)
- Kinetic energy
There are 2 types of currents:
- Direct Current (DC) – Where electrons flow in the same direction in a wire.
- Alternating Current (AC) – electrons flow in different directions in a wire
There are 2 types of circuits:
- Series Circuit: the components are lined up along one path. If the circuit is broken, all components turn off.
- Parallel Circuit – there are several branching paths to the components. If the circuit is broken at any one branch, only the components on that branch will turn off.
Conductors and Insulators
- Conductors – material through which electric current flows easily.
- Insulators – materials through which electric current cannot move.
What Influences Resistance?
- Material of wire – aluminum and copper have low resistance
- Thickness – the thicker the wire the lower the resistance
- Length – shorter wire has lower resistance
- Temperature – lower temperature has lower resistance
Voltage
- The measure of energy given to the charge flowing in a circuit.
- The greater the voltage, the greater the force or “pressure” that drives the charge through the circuit.
Atoms…
- Have neutrons, protons, and electrons.
- Protons are positively charged.
- Electrons are negatively charged.
Electrons…
- Are located on the outer edges of atoms…they can be moved.
- A Concentration of electrons in an atom creates a net negative charge.
- If electrons are stripped away, the atom becomes positively charged .
Law of Charges
a. Opposite charges attract.
b. Like charges repel.
Static Electricity
- The build up of an electric charge on the surface of an object.
- The charge builds up but does not flow.
- Static electricity is potential energy. It does not move. It is stored.
Static Discharge from Static Electricity
Occurs when there is a loss of static electricity due to three possible things:
- Friction - rubbing
- Conduction – direct contact
- Induction – through an electrical field (not direct contact)
Current Electricity
Current: The flow of electrons from one place to another.
- Measured in amperes (amps)
- Kinetic energy
There are 2 types of currents:
- Direct Current (DC) – Where electrons flow in the same direction in a wire.
- Alternating Current (AC) – electrons flow in different directions in a wire
There are 2 types of circuits:
- Series Circuit: the components are lined up along one path. If the circuit is broken, all components turn off.
- Parallel Circuit – there are several branching paths to the components. If the circuit is broken at any one branch, only the components on that branch will turn off.
Conductors and Insulators
- Conductors – material through which electric current flows easily.
- Insulators – materials through which electric current cannot move.
What Influences Resistance?
- Material of wire – aluminum and copper have low resistance
- Thickness – the thicker the wire the lower the resistance
- Length – shorter wire has lower resistance
- Temperature – lower temperature has lower resistance
Voltage
- The measure of energy given to the charge flowing in a circuit.
- The greater the voltage, the greater the force or “pressure” that drives the charge through the circuit.
