Physics- light and magnetism

• Reflection


  Bounces off the surface
• Refraction


  Changes the speed or direction of the light
• Specular reflection


  Reflection of light off a smooth surface
• Diffuse scattering


  Reflection of light on a rough surface
• What happens when light passes through a prism

  It is refracted and separated into all of the different colors that represent each of the wavelengths and frequencies
• How a simple camera forms an image

  A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image
• How primary colours add to make secondary colours

  Light in these colours can be added (combined) together to make the secondary colours
• How a filter subtracts light

  Filters isolate individual colours by removing the other colours, so this process is often referred to as colour separation by subtraction
• How coloured materials subtract light


  If the shirt absorbs blue light, then only red and green light will be reflected from the shirt

  Hint: It is a blue
• Magnets


  They repel and attract
• Magnetic fields


  • Magnetic fields are represented by diagrams which show patterns of magnetic field lines
• magnetic field


  The magnetic field of the Earth is generated by electric currents flowing in its molten iron core
• How to make an electromagnet

  By wrapping a solenoid around an iron core and connecting a power source
• Changing the strength of an electromagnet

  • Increasing current
  • Increasing the number of turns of the coil
  • Adding an iron core
• Uses of an electromagnet

  • Loudspeakers, motors and electric bells