Electricity and Magnetism Flashcards
What is Electrical Energy? (3 Main Points)
- Electrical energy is a type of kinetic energy.
- The movement of electrons from negative to positive (because electrons have a negative charge).
- It is a convenient form of energy because it can easily be changed into other forms of energy like light and sound.
What is Current Electricity ?
Current electricity is the flow of electrons through a electrical conductor.
What is Static Electricity?
Static electricity occurs when charges collect on surfaces (insulators) and do not flow away immediately
What are Conductors? (2 Main Points)
- In some materials, called conductors, some of the electrons are free to leave.
- They can flow through the conductor in an electric current.
What are Insulators? (2 Main Points)
- In other materials, called insulators, the electrons are tightly held and cannot leave.
- Electrical current will not flow but static electricity can build up.
What happens to the charge of objects when they are rubbed together, and how do charges interact?
Rubbing transfers electrons: gain = negative charge, lose = positive charge. Opposite charges attract; like charges repel.
What is the Danger of Static Electricity
- Static sparks near petrol can ignite fumes, causing fires.
- Lightning rods protect buildings by safely directing static charges from lightning into the ground.
What are the uses of Static Electricity?
Photocopiers, Defibrilatiors, and Printers
What are the three components of Electrical Circuits?
- An energy supply - cell or a battery of cells
- A component to transfer electrical energy into another form - e.g light bulb
- A complete & unbroken pathway for the electrons to flow - usually made of copper wires
What is Current? (3 Main Points)
- Current is a measure of flow of electrical charge in a circuit
- Current is measured in amps (A) using an ammeter
- Ammeters must be connected in series
What is Conventional Current?
Before the discovery of electrons, scientists thought that current was the movement of positively charged from the positive to the negative terminal.
What is Electron Flow defined as?
Charge carried by electrons from the neg (-) to the pos (+) terminal.
Define the Current in Series? (2 Main Points)
- In a series circuit, current flows through one continuous pathway
- The current is the same in all parts of a series circuit
Define the Current in Parallel? (2 Main Points)
- In a parallel circuit, the current divides at the point where the circuit branches and then recombines to complete the circuit.
- The current is shared between branches in a parallel circuit.
What is the Voltage? (4 Main Points)
- Voltage is the energy (or “push”) for electrons to flow in a circuit.
- It’s the difference in electrical potential between two points, also called potential difference.
- Adding batteries increases voltage.
- Measured in volts (V) using a voltmeter, which connects in parallel.