PHYSICS - Knowledge Part

• ELECTROMAGNETIC WAVES


  Also called as electromagnetic radiation.
•  EM waves are created due to vibrations between an electric field and a magnetic field that crosses over to each other in oscillating motion
• EM waves are transverse waves, which means both electric and magnetic fields oscillate perpendicular to each to the direction of motion of the wave
• electromagnetic radiations

  are oscillations produced due to crossing over of an electric and a magnetic field wherein the electric and magnetic field vector are always perpendicular to each other and perpendicular to the direction of the propagation. 
• Wavelength (λ) i


  the distance between two corresponding points in a wave train. It can be expressed in meter (m) unit.
• Frequency (f)


  refers to the number of waves passing through a given point in a 

  given time. It is expressed in Hertz (Hz) or s-1.
• the longer the wavelength the lesser its frequency 

  and vice versa.
• he amount of Energy (E) carried by the Electromagnetic waves is expressed in Joules (J)
• EM waves can travel to a vacuum (empty space)
• EM waves have an electric field that travel and move perpendicularly with magnetic field
• ELECTROMAGNET


  • a current-carrying coil with magnetic properties.
• Electromagnet’s magnetic field strength can be increased by…

  * increasing the amount of current

  * increasing the number of turns of wire in the coil

  * using an iron core
• ELECTROMAGNETIC INDUCTION

  • the process of generating electric current with a magnetic field. 
• • The current produced by electromagnetic induction is greater when the magnet or coil moves faster, the coil has more turns, or the magnet is stronger.
• If the magnet or coil is moved back and forth repeatedly, alternating current (AC) is produced
• ELECTRIC MOTOR


  a device that converts electrical energy to rotational mechanical energy.

  Battery

  Brush

  Magnet

  Armature
• ELECTRIC GENERATOR


  a device that converts electrical energy into mechanical energy.