Physics Paper 1 Summary

8 energy stores

-Kinetic

-Thermal

-Chemical

-Gravitational Potential

-Elastic Potential

-Nuclear

-Magnetic

-Electrostatic

4 Energy Transfers

-Mechanically

-By heating

-Electrically

-Radiation

Ways to Generate Electricity

Non Renewable and Renewable Resources

Non Renewable Resources: Fossil Fuels

Fossil fuels are made out of remains of living organisms that died millions of years ago

Advantages of Fossil Fuels

They are reliable and release a great deal of energy, they are also abundant and relatively cheap and they are extremely versatile

Disadvantages of Fossil Fuels

Produces carbon dioxide which is a greenhouse gas which leads to global warming

Nuclear Energy

Releases energy form nuclear reactions

Advantages of Nuclear Energy

It is extremely reliable and does not release carbon dioxide therefore does not contribute to climate change

Disadvantages of Nuclear Power

Contains highly dangerous radioactive material and dismantling a nuclear power plant takes many years and is extremely expensive

Advantages of Wind Turbines

Wind is a naturally replenishing resource so it will not run out and they do not produce pollutants

Disadvantages of Wind Turbines

Unreliable as it is dependant on the speed of the wind

Advantages of Solar Panels

Solar panels produce electricity without emitting greenhouse gase , reducing climate change impact.

Disadvantage of Solar Panels

Dependent on the sun, so on cloudy day, its ineffective

Advantages of Wave Power

Uses turbines to produce electricity therefore does not affect climate change

Disadvantages of Wave Power

Could be harmful to marine life

Advantages of Tidal Barriers

Uses turbines that use energy from tides going up and down therefore not affecting climate change.

Disadvantage of Tidal Barriers

Can potentially kill marine life and need a suitable location to construct them

Advantages of Hydroelectric Energy

Uses turbines in a valley to generate electricity therefore not affecting climate change.

Disadvantages of Hydroelectric Power

Can only be built in limited locations and can disrupt the ecosystem by destroying habitats

Advantages of Geothermal Energy

Its renewable and provides a reliable and constant power source

Disadvantages of Geothermal Energy

Can only be used in Volcanic Areas

Advantages of Biofuels

They are produced from plant materials which are burnt however they do not add any extra carbon dioxide to the atmosphere therefore it is carbon neutral

Disadvantage of Biofuels

If we use land to grow crops for fuel, that could increase food prices

Circuit Symbols

I-V Graph: Ohmic Conductor

The current through an ohmic conductor at constant temperature is directly proportional to potential difference so you get a straight line passing through the origin

I-V Graph: Filament Lamp

As the current increases, the temperature of the filament increases so the resistance increases. This means less current can flow per unit of potential difference so the graph gets shallower.

I-V Graph: Diodes

Current will only flow in one direction as diodes have a high resistance in the reverse direction.

Thermistors

Decreased resistance when surroundings get hot and increased resistance when surroundings get cold

In series circuits, current is the ? Potential difference is ? Resistance ?

Current is the same everywhere and Potential Difference is shared between the components, Resistance increases as you add more resistors

In Parallel Circuits, the current ? The potential difference ? Resistance ?

The current is shared so it splits between branches and the Potential Difference is the same, Resistance decreases as you add more resistors.

Alternating Current is used in the ?

Uk’s Mains Supply which is 230 Volts and 50Hz

The three core cables

Live wire (Brown) containing 230V, Neutral wire (Blue) which completes the circuit (0V), Earth wire (Green and Yellow) which is for safety (0V)

The Earth Wire

Used when the live wire comes in contact with the metal casing of an appliance

The National Grid

Where electricity leaves power stations and passes through a step up transformer which increases potential difference and decreases current so that less energy is lost due to heat at the transmission cables, it is then distributed around the country and goes through a step down transformer which reduces the potential difference to 230V and increases the current in order to be passed to homes