describe the energy transfers that take place when a system is changed by work done when a current flows through a component

explain, with reference to examples, how the power transfer in any circuit device is related to the energy transferred from the power supply to the device and its surroundings over a given time:

power (W) = energy (J) ÷ time (s)

recall and use the relationship between the potential difference across the component and the total charge to calculate the energy transferred in an electric circuit when a current flows through a component:

energy transferred (work done) (J) = charge (C) × potential difference (V)

recall and apply the relationships between power transferred in any circuit device, the potential difference across it, the current through it, and its resistance:

power (W) = potential difference (V) × current (A)

power (W) = (current (A))² × resistance (Ω)

use the idea of conservation of energy to show that when a transformer steps up the voltage, the output current must decrease and vice versa

a) select and use the equation:
potential difference across primary coil × current in primary coil = potential difference across secondary coil × current in secondary coil

explain how transmitting power at higher voltages is more efficient way to transfer energy