Paper clip motor
This motor demonstrates the Lenz's law clearly. i.e., passing a current through the coil creates a magnetic field around the coil, which consists with a magnetic field of magnet. Action of this resultant force is half–rotation of the coil. Insulated ends of the coil axes provide closing and opening the circuit and makes the coil to go in constant spin. This DC motor is able to spin in one direction determined by the poles of the permanent magnet. If the poles of the magnet are changed, then the spinning direction of the coil too changes.
GPS tracking system
It can be used to track a boat (or an entire fleet) from anywhere in the world with an internet connection. A boat's precise voyage and exact location can be viewed on Google Earth. The new reports coming from the GPS Tracker, through the satellite, are automatically updated to the server. The server sends an email and text message to the client's mobile located anywhere in the world.
Electricity and magnetism are two
aspects of the same force. Faraday's law describes how a time varying
magnetic field induces an electric field. This aspect of electromagnetic
induction is the operating principle behind many electric generators. A
rotating bar magnet creates a changing magnetic field, which in turn
generates an electric field in a nearby wire. Maxwell's correction to
Ampere's law shows that not only a changing magnetic field induces an
electric field, but also a changing electric field induces a magnetic
Maxwell found a set of equations that describe how electric and
magnetic fields interact with each other. Maxwell's equations explain how
an electromagnetic wave moves. As the electric wave moves through space,
energized by charges moving in a wire, it is varying. The varying
electric wave creates a magnetic wave which is also varying and moves
alongside the electric wave. The varying magnetic wave in turn creates
an electric wave, which moves alongside the magnetic wave. The overall
effect, described with precision by Maxwell's equations, is of a
combined electromagnetic wave moving through space with the electric and
magnetic components in step with one another.
The speed calculated for electromagnetic waves, which could be predicted
from experiments on charges and currents exactly matches the speed of
Light, X–rays and radio waves are different forms of
electromagnetic radiation with varying frequencies. Maxwell understood
the connection between electromagnetic waves and light and unified the
theories of electromagnetism and optics. Electromagnetic theory ties
together such broad phenomena such as electrical energy transmitted at
frequencies as low as 50 hertz, high frequency radio waves and light.
The many facets of electromagnetic waves are due to how waves behave at
different frequencies and how materials react in different ways to waves
of different frequency.
We find the applications of electricity and magnetism in various
fields such as power generation and telecommunications. Communication
satellites are so much a part of every day life that we use them without
realizing it. They relay radio, television, telephone and data signals
from one part of the earth to another through electromagnetic waves at
different frequencies. Navigation satellites transmit radio signals that
enable navigators to determine their position. Global Positioning
System (GPS) uses satellites in this way. Many mobile telephone networks
use electromagnetic waves at microwave frequencies to transmit and
receive signals with in small areas called 'cells'.