| The flow of electric charge in a circuit. | Electric Currents |
| What do electric currents cause in a circuit? | Energy Transfers. |
| The opposition to the flow of electric current. | Resistance |
| What happens when current flows through a circuit with resistance? | Work is done against the resistance. |
| The transfer of energy resulting from the application of force. | Work Done |
| How is energy transferred in a circuit with resistance? | Through the work done against the resistance. |
| The production of heat as a result of electric current passing through a conductor. | Heating Effect |
| What is the primary energy transfer in a circuit with resistance? | Heating. |
| The energy stored in the form of heat. | Thermal Energy Stores |
| Where is the energy transferred in a circuit with resistance stored? | In the thermal energy stores of the surroundings. |
| Energy transfer that serves a purpose or performs work. | Useful Energy Transfer |
| In what devices is the heating effect of electric currents a useful energy transfer? | Kettles, heaters, toasters. |
| Energy transfer that does not serve a purpose or perform useful work. | Non-useful Energy Transfer |
| In what devices is the heating effect of electric currents a non-useful energy transfer? | Computers, phones. |
| Energy that is scattered and spread out in the surroundings. | Dissipated Energy |
| Where does the energy transferred in a non-useful energy transfer go? | It is dissipated into the thermal energy stores of the surroundings. |
| The ratio of useful energy output to total energy input. | Energy Efficiency |
| How does the concept of energy efficiency relate to useful and non-useful energy transfers in devices? | Energy efficiency is higher when more energy is transferred for useful work and less is dissipated as non-useful heat. |
| Materials through which electric current can flow. | Conductors |
| What is the typical atomic structure of metals? | A lattice of ions with delocalised electrons. |
| Ions arranged in a regular, repeating pattern. | Lattice Ions |
| What surrounds the lattice ions in metals? | Delocalised Electrons. |
| Electrons that are not fixed to a particular atom and can move freely within a material. | Delocalised Electrons. |
| What happens when a potential difference is applied to a metal conductor? | Delocalised electrons begin to flow. |
| The flow of electric charge, usually carried by electrons. | Electric Currents |
| What causes a transfer of energy in a metal conductor carrying current? | Collisions between electrons and lattice ions. |
| Interactions between particles that result in changes in their motion. | Collisions |
| What happens to the lattice ions when electrons collide with them in a metal conductor? | The lattice ions vibrate more. |
| Rapid movements back and forth or oscillations. | Vibrations |
| What effect do increased vibrations of lattice ions have on the metal conductor? | It heats up. |
| The transfer of thermal energy. | Heat |
| What determines the magnitude of energy transfer in a metal conductor carrying a current? | The current; the bigger the current, the greater the transfer of energy. |
| The rate at which electrons move through a conductor. | Electron Speed |
| How does the speed of electrons relate to the number of collisions and energy transfer in a conductor carrying a current? | The faster the electrons move, the more collisions and greater the energy transfer. |
| The movement of energy from one place to another. | Energy Transfers. |
| What is the primary mechanism of energy transfer in a metal conductor carrying a current? | Collisions between electrons and lattice ions, leading to increased vibrations and heating. |
| Energy losses that occur in a system and are not useful for the intended purpose. | Unwanted Energy Transfers |
| What causes unwanted energy transfers in electrical systems? | Resistance in wires leading to heating and energy loss. |
| The opposition to the flow of electric current in a conductor. | Resistance |
| Why do wires heat up and lose energy when electricity is transferred over long distances? | Due to the resistance in the wires. |
| Materials or wires that offer less opposition to the flow of electric current. | Low Resistance |
| How can unwanted energy transfers be reduced in electrical systems? | By using low resistance wires. |
| Metals like copper and aluminium, which have lower resistance due to the spacing of lattice ions. | Metals with Low Resistance |
| Why do metals like copper and aluminium have lower resistance compared to others? | Lattice ions are further apart in these metals. |
| Wires with a larger cross-sectional area. | Thick Wires |
| How does the thickness of a wire affect its resistance? | Thick wires have lower resistance compared to thin wires. |
| A network of electricity transmission lines, substations, transformers, and more, used for the distribution of electrical power on a large scale. | National Grid |
| What type of wires does the National Grid use to reduce energy loss? | Thick wires made of aluminium. |
| The ratio of useful energy output to the total energy input in an electrical system. | Electrical Efficiency |
| How does using low resistance wires contribute to electrical efficiency? | It reduces energy losses in the form of heat. |
| The measure of the extent of a surface within a plane. | Cross-Sectional Area |
| What does the thickness of a wire refer to in terms of its cross-sectional area? | A larger cross-sectional area corresponds to a thicker wire. |
| The amount of energy transferred by an electric circuit. | Electrical Energy |
| What is the equation for calculating electrical energy? | Electrical Energy (E) = Current (I) × Voltage (V) × Time (t). |
| The flow of electric charge in a circuit, measured in amperes (A). | Current (I) |
| What is the unit of measurement for current? | Amperes (A). |
| The electric potential difference between two points in a circuit, measured in volts (V). | Voltage (V) |
| What is the unit of measurement for voltage? | Volts (V). |
| The duration for which current flows in a circuit, measured in seconds (s). | Time (t) |
| What is the unit of measurement for time in electrical energy calculations? | Seconds (s). |
| Calculate the electrical energy transferred if a kettle takes 90 seconds to boil with a current of 9 A and a potential difference of 230 V. | Electrical Energy (E) = 9 A × 230 V × 90 s = 186,300 J (joules). |
| The rate at which electrical energy is transferred or used, measured in watts (W). | Electrical Power |
| How is electrical power related to electrical energy? | Power (P) = Energy (E) ÷ Time (t). |
| The process of converting one unit of measurement to another. | Unit Conversion |
| How is joules (J) converted to kilowatt-hours (kWh)? | Divide the energy in joules by 3,600,000 (1 kWh = 3,600,000 J). |
| Why is it important to calculate electrical energy in real-life scenarios? | To assess energy consumption, costs, and efficiency of electrical devices. |
