PHYSICS

• James Clerk Maxwell described light as a propagating wave made up of electric and magnetic field.
• Maxwell's work revealed that electromagnetic radiation come from oscillating electric and magnetic fields
• This electromagnetic field has been associated with electromagnetic (EM) waves, in which light is a component.
• Electromagnetic waves describe propagating oscillations with respect to electric and magnetic fields.
• Speeds of the waves depend on the combination of constants involved in electrostatics and magnetism.
• Light must be an EM disturbance in the form of waves propagating through EM field in accordance of EM Laws.
• An electromagnetic wave is understood to be a transverse wave produced by a vibrating electric charge.
• Electromagnetic waves possesses the characteristics of

  *wavelength

  *speed

  *frequency
• Wavelength is the measurement of the distance between the successive crests (highest point) and throughs (lowest point)
• 300M is the speed of light
• Types of wave

  • Transverse wave
  • Longitudinal wave
• The frequency is the number of waves that propagate in a unit of time, which is usually in seconds. The speed is how fast the wave is propagating.
• Transverse wave is a wave in which the movement of the energy is perpendicular to the movement of the particle of the wave.
• Longitudinal wave is a wave with the energy moving parallel to the movement of the particle of the wave
• What is the type of ray?

  Normal line/ Invisible Line

  Reflected Ray

  Incident Ray

  A) normal line or invisible line

  B) reflected light/ray

  C) incident ray

  D) point of incident

  
• Properties of wave

  • Electric permittivity
  • Magnetic Permeability
• Electric permittivity is related to the energy stored in an electric field.
• Magnetic permeability is similar to the energy stored in a magnetic field
• When light strikes a material, it has the capacity to bounce against it or be reflected. This phenomenon is known as the reflection of light, and it is governed by the law of reflection
• The incident ray, the reflected ray, and the normal to the surface all lie on the same plane
• Mirrors are most commonly used to represent such reflecting surfaces.
• Types of reflection

  • Regular or Specular Reflection
  • Diffuse Reflection
• Regular/Specular reflection occurs on a smooth surface. Reflected rays have only one direction.
• Diffused reflection occurs on a rough surface. Reflected rays have varying directions.
• Total internal reflection - The phenomenon which occurs when the light rays travel from a more optically denser medium to a less optically denser medium.
• Since it passes from a medium of a higher refractive index to that having a lower refractive index, the refracted light ray bends away from the normal.
• Identify the correct answer

  *Reflection - go through

  A) refraction

  B) critical angle

  C) reflection

  
• Two condition of total internal reflection

  • The light ray move from the denser medium to a light denser medium
  • The angle of incidence must be greater than the critical angle
• Example of total internal reflection

  • Mirage
  • Optical Fiber
• Mirage - It is an optical illusion that is responsible for the appearance of the water layer at short distances in a desert or on the road.
• Optical Fiber - When the incident ray falls on the cladding, it suffers total internal reflection as the angle formed by the ray is greater than the critical angle. It revolutionized the speed with which signals are transferred, not only across cities but across countries and continents making telecommunication one of the fastest modes of information transfer.