- When some insulating materials are rubbed together they become electrically charged because electrons move from one insulating material to the other.
- Charged objects with different charges will attract each other. Charged objects with the same charge will repel each other.
- When a charge flows through a conductor this is called a current.
- If conductor is earthed then the electrons will flow down to the earth and the conductor will be discharged.
- Electrostatics is used for a number of reasons. However, it can be dangerous so earthing and antistatic materials are used.
- Standard symbols are used to represent different electrical components in circuit diagrams.
- If the temperature of the resistor is kept constant then the line will always be straight. This means that current is directly proportional to the potential difference across the resistor.
- v = c x r
- At a constant temperature, the resistance stays constant.
- A diode only lets a current flow in one direction.
- In a light-dependent resistor (LDR) the resistance becomes smaller as the light shining on it increases in brightness.
- As a thermistor temperature increases its resistance decreases.
- In order for a circuit to work it must be complete and there can be no short circuits.
- In a series circuit the current which flows through each component is the same and the components share the potential difference.
- current = potential difference of supply / total resistance
- In a parallel circuit the current is shared between each component and the parallel difference of each component is the same
- The flow of electric charge is called the electric current.
- I = Q / t
- In order for a current to flow through an electrical component a potential difference (or voltage) is required.
- V = W / Q
- The more cells there are in a circuit the larger the current flowing and so more current will flow through the components as long as they’re connected in opposite directions.