PHYSICS Paper 1:

Renewable energy

Sources of energy that are replenished naturally, such as solar and wind.

Efficiency

A measure of how much useful energy is produced compared to the total energy input, expressed as a percentage.

Joule

The standard unit of energy in the International System of Units (SI).

Kinetic energy

The energy possessed by an object due to its motion.

Gravitational potential energy

The energy stored in an object as a result of its height above the ground.

Specific heat capacity

The amount of energy required to raise the temperature of one kilogram of a substance by one degree Celsius.

Watt

The unit of power, equivalent to one joule per second.

Work done

The energy transferred when a force is applied over a distance.

Conduction

The transfer of heat through a material without the movement of the material itself.

Convection

The transfer of heat by the movement of fluids, such as air or water.

Lubricant

A substance used to reduce friction between surfaces in mutual contact.

Elastic potential energy

The energy stored in elastic materials as the result of their stretching or compressing.

Energy conservation

The principle that energy cannot be created or destroyed, only transformed from one form to another.

Power formula

A mathematical expression that relates power to work done and time.

LED

A type of light bulb that is highly energy-efficient and has a long lifespan.

Double glazing

A window construction that uses two layers of glass with an air gap to reduce heat loss.

Sankey diagram

A visual representation of energy transfer, showing energy input, useful output, and wasted energy.

Electric fan

An appliance that converts electrical energy into kinetic energy to create airflow.

Energy transfer in hairdryer

The conversion of electrical energy into thermal, kinetic, and sound energy.

Kilowatt-hour

A unit of energy commonly used to measure electricity consumption.

Photovoltaic cells

Devices that convert sunlight directly into electricity.

Chemical energy

Energy stored in the bonds of chemical compounds, such as food and batteries.

Heat

The form of energy that is often wasted by light bulbs, primarily due to inefficiencies.

Coal

A fossil fuel that is known for emitting high levels of carbon dioxide when burned.

Energy formula using charge

An equation that calculates energy transferred based on electric charge and voltage.

Hydroelectric power

A renewable energy source that harnesses the energy of flowing water.

Loft insulation

Material used to reduce heat loss from the roof space of a building.

Fossil fuels

Natural energy sources formed from the remains of ancient organisms, which take millions of years to regenerate.

Kettle power rating

The typical power consumption of a kettle, usually around 2 kilowatts.

Power rating

A measure of how much energy an appliance uses per second.

Specific heat capacity meaning

Indicates the amount of energy needed to increase the temperature of a substance.

Cavity wall insulation

Insulation that traps air between walls to minimize heat loss.

Radiation

The transfer of heat in the form of electromagnetic waves.

Voltage in UK homes

The standard electrical voltage supplied to homes in the UK, typically 230 volts.

Thermal conductivity

A property that measures how well a material conducts heat.

Copper

A metal known for its high thermal conductivity, making it ideal for electrical wiring.

Polystyrene

A material that is an effective insulator due to its ability to trap air.

Cost formula using kWh

An equation that calculates the cost of electricity based on power, time, and price per unit.

Specific heat capacity unit

Measured in joules per kilogram per degree Celsius (J/kg°C).

Energy wastage causes

Factors such as friction, resistance, and unwanted heat that lead to energy loss.

Wasted energy dissipation

The process by which wasted energy spreads into the surrounding environment.

Best radiation emitter

Surfaces that are dull and black are most effective at emitting thermal radiation.

Most efficient energy resource

Hydroelectric power, known for minimal energy loss during generation.

Power measurement

The rate at which energy is transferred or converted.

Insulation

Materials designed to reduce the transfer of heat or electricity.

Kinetic energy in a moving car

The energy associated with the motion of the vehicle.

Energy change in falling object

The transformation of gravitational potential energy into kinetic energy.

Ampere

The unit of electric current.

Voltage, current, resistance formula

An equation that relates voltage, current, and resistance in an electrical circuit.

Ohm

The unit of electrical resistance.

Voltage unit

The measure of electric potential difference, expressed in volts.

Volt

The unit of measurement for electrical potential difference.

Fuse

A safety device that melts and breaks the circuit if the current exceeds a certain level.

Mains Voltage

The standard voltage supplied to homes and businesses, typically around 230 V in the UK.

Alternating Current (AC)

An electric current that periodically reverses direction.

Direct Current (DC)

An electric current that flows consistently in one direction.

Frequency

The number of cycles per second in an alternating current, measured in Hertz (Hz).

Earth Wire

A safety wire that grounds excess current to prevent electric shock.

Live Wire

The wire that carries the current to the appliance, typically colored brown in the UK.

Neutral Wire

The wire that completes the circuit by carrying current away from the appliance, typically colored blue in the UK.

Earth Wire Color

The wire that provides safety by grounding, colored green and yellow in the UK.

Energy Transfer Formula

A formula that calculates energy transferred, expressed as Energy = power × time.

Energy Formula

A formula that links energy, charge, and voltage, expressed as E = Q × V.

Ohmic Conductor

A material that follows Ohm's law, where current and voltage are directly proportional.

Filament Lamp Graph

A graph that shows a curve, indicating that resistance increases with temperature.

Diode

A semiconductor device that allows current to flow in one direction only.

Total Resistance in Series

The total resistance in a series circuit, calculated by adding all individual resistances.

Current in Parallel Circuit

In a parallel circuit, current is divided among the branches.

Voltage in Parallel Circuits

In parallel circuits, the voltage remains constant across all branches.

National Grid

A network of cables and transformers that distribute electricity across regions.

Voltage Increase for Transmission

Increasing voltage before long-distance transmission reduces current and energy loss as heat.

Step-Up Transformer

A device that increases voltage and decreases current.

Step-Down Transformer

A device that decreases voltage to safe levels.

Kettle Fuse Rating

A typical fuse rating for a kettle is 13 A.

Resistor

A component that limits the flow of electric current.

Static Electricity

Electric charge that builds up on the surface of objects due to friction.

Electric Field

A region around a charged object where electric forces can be felt.

Touching Live Wire

Contact with a live wire can result in an electric shock.

Resistance and Wire Length

As the length of a wire increases, its resistance also increases.

Low Resistance Material

Copper is commonly used due to its low resistance.

Double Insulation

A safety feature that prevents any exposed metal parts, protecting the user.

Current and Voltage Relationship

If voltage increases while resistance remains constant, current also increases.

Household Lighting Circuit

Household lighting typically uses a parallel circuit.

Total Resistance in Parallel

Adding more branches to a parallel circuit decreases the total resistance.

Variable Resistor

A resistor whose resistance can be adjusted.

Thermistor

A type of resistor that decreases resistance as temperature increases.

LDR (Light Dependent Resistor)

A resistor that decreases resistance as light intensity increases.

Fuse Symbol

In circuit diagrams, a fuse is represented by a rectangle with a line through it.

Heater Energy Transfer

A heater transfers energy from electrical to thermal.

Power Calculation

Power can be calculated using the formula P = IV, where I is current and V is voltage.

Resistance Formula

Resistance can be calculated from voltage and current using R = V / I.

Charge Unit

The unit of electric charge is the Coulomb (C).

Circuit Breaker

A device that interrupts the circuit when the current exceeds a safe level.

Resistance Effect on Current

Higher resistance results in lower current.

Alternating Current Definition

A type of current that reverses its direction periodically.

Direct Current Definition

A type of current that flows consistently in one direction.

Plug Safety Features

Safety features in a plug include a fuse, earth wire, and insulation.

Displacement

The volume of fluid displaced by an object when it is submerged.

Internal Energy

The total kinetic and potential energy of the particles within a substance.

Change of State

A transformation between solid, liquid, and gas phases where temperature remains constant.