what is electromagnetism
Answers
Electromagnetism is the theory that explains the close relationship between electric and magnetic fields. Variations in an electric field produce variations in the associated magnetic field, which then produce variations in the electric field, and so on. These variations are called electromagnetic waves, and they propagate outward at the speed of light. Depending on the frequency of vibration of the electrons producing the field, these EM waves are called:
radio waves
microwaves
infrared light
visible light
ultraviolet light
x-rays
gamma rays, or
cosmic waves,
in order of increasing frequency, in cycles per second, or Hertz (Hz).
Electromagnet is a temoprary magnet because it loses the property of magnetism when the current stops flowing through it.
It works on the principal of magnetic effect of current.
It is made up of a current carrying coil of an insulated wire wrapped on a cylindrical core.