| Energy transfers inside of a kettle | Electric to thermal |
| Energy transfers inside of a fan | Electric to kinetic |
| What is potential difference? | Energy transferred per charge passed |
| How is energy transmitted across the National Grid? | Transmits electricity at high p.d. (400 000V) and low current across the UK from power stations to homes and industry. |
| What do step-up transformers have? | More turns on the secondary coil than the primary coil. |
| What do step-up transformers do? | Increase the p.d to 400 000V, reducing current. |
| What do step-down transformers have? | More turns on the primary coil than the secondary coil. |
| What do step-down transformers do? | Reduce p.d from 400 000V, increasing current. |
| How is the efficiency of energy transfer increased in the National Grid? | The current doesn't heat the cables as much as a higher current would, so less heat is loss by thermal dissipation. |
| What causes a static charge? | A transfer of electrons between insulating materials rubbed together, leaving them oppositely charged. |
| After a polythene rod and a cloth duster are rubbed together which has which charge? What has happened? | Rod- negative
Cloth- positive
Electrons transferred from cloth onto rod. |
| After an acetate rod and a cloth duster are rubbed together which has which charge? What has happened? | Rod- positive
Cloth- negative
Electrons transferred from the rod to the cloth. |
| What happens to p.d. as electric charge builds on an object? | It increases from 0V |
| How is a spark caused from the electric charge? | When the p.d. between the object and the earth gets large enough, electrons can jump between the gap causing a spark. |
| Is electrostatic attraction/repulsion a contact or non-contact force? | Non-contact |
| Where are electric fields found? | Around any charged object |
| Which way do electric field lines point? | Positive to negative |
| What do closer electric field lines show? | A stronger electric field |
| What happens as you increase the distance between charged objects? | The strength of field decreases and the force between them decreases |
| What do high p.d.s cause between charged and earthed objects? | Strong electric fields |
| What does a strong field do to air particles? | It removes electrons (ionises), allowing current to flow through it. |
