Mains Electricity: safety

Posted in AQA GCSE P2, P2: Mains Electricity by Mr A on 1 Mar 2010

 

  • Electricity is dangerous!
  • Structure of cables
  • Fuses
  • Earth wire
  • Three-pin plugs

 


 

Electricity is dangerous!

An electric shock can affect your muscles and nerves; it can paralyse you or stop your heart beating. You can get an electric shock from anything plugged in to the mains.

 


 

Structure of cables

 

 

 

Wires are coated in plastic for safety. The metal wires allow a current to flow as they conduct electricity. The plastic coating is an insulator which prevents people from being electrocuted.

 


 

Fuses

 

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Earth wire

 

The most dangerous thing that can go wrong with an appliance is that the live wire becomes loose inside and touches the casing. If the casing is metal it will become live. If you touch the casing, you will get an electric shock.

 

The earth wire is connected to the inside of the casing. Then, if the live wire touches the casing, charge will flow through the earth wire (rather than you), and the fuse will blow.

 

 

 


 

Three-pin plugs

 

 

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Investigating Resistance Wire

Posted in AQA GCSE P2, P2: Current Electricity by Mr A on 20 Jan 2010

Current Electricity Introduction

Posted in AQA GCSE P2, P2: Current Electricity by Mr A on 18 Jan 2010

Types of Energy

Posted in AQA GCSE P1a, P1a: Conservation of Energy by Mr A on 9 Jan 2010

Energy describes the amount of work that can be done by something.
There are many different types of energy…

  • Kinetic energy (KE) is the energy of movement: the faster something is moving the more KE it has.
  • Gravitational potential energy (GPE) is energy associated with position: the higher something is the more GPE it has.
  • Chemical energy is energy stored in chemical bonds, and may be released when chemical reactions take place. It includes energy stored in food, fuel, or in our bodies.
  • Elastic potential energy is the energy stored in a spring or a rubber band when it is stretched.
  • Electrical energy is the energy transferred by an electric current. Note that batteries store chemical energy, which is converted to electrical energy only when they are being used.
  • Thermal energy is the energy something has due to its temperature. It is actually the KE of its moving particles.
  • Nuclear energy is energy stored in atomic nuclei, released in nuclear fission and fusion.
  • Electromagnetic energy is the energy of a light source, or a source of any type of electromagnetic wave.
  • Sound energy is the energy of vibrating air particles, which we hear as sound. It is really a form of KE.

What forms of energy do each of the following things have?

Introduction to Capacitors

Posted in A2 Unit 4: Capacitors, AQA A2 Unit 4 by Mr A on 18 Nov 2009
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