4.2.4 Energy transfers

Explain how the power transfer in any circuit device is related to the potential difference across it and the current through it

Calculate power by recalling and applying the equations: [ P = VI ] and [ P = I2 R ]

Describe how appliances transfer energy to the kinetic energy of motors or the thermal energy of heating devices

Calculate and explain the amount of energy transferred by electrical work by recalling and applying the equations: [ E = Pt ] and [ E = QV ]

Explain how the power of a circuit device is related to the potential difference across it, the current through it and the energy transferred over a given time.

Describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in stored energy when they are in use

Identify the National Grid as a system of cables and transformers linking power stations to consumers

Explain why the National Grid system is an efficient way to transfer energy, with reference to change in potential difference reducing current

4.2.1 Current, potential difference and resistance

4.2.2 Series and parallel circuits

4.2.3 Domestic uses and safety